Phosphazene compound, photosensitive resin composition and use thereof

ABSTRACT

Disclosed is a phosphazene compound and a photosensitive resin composition. The phosphazene compound is obtained by reacting a phenoxyphosphazene compound (A-1) having a phenolic hydroxyl group and/or a cross-linked phenoxyphosphazene compound (A-2) obtained by cross-linking the phenoxyphosphazene compound (A-1) with an epoxy compound (B) having an unsaturated double bond and/or an isocyanate compound (C), wherein the phosphazene compound has an unsaturated double bond in its molecule. The photosensitive resin composition includes at least: a soluble polyimide resin (G-1) having a carboxyl group and/or a hydroxyl group and is soluble in an organic solvent, as the polyimide resins (G); and a phenoxyphosphazene compound (H-1) having a phenolic hydroxyl group and/or a cross-linked phenoxyphosphazene compound (H-2), which is obtained by cross-linking the phenoxyphosphazene compound (H-1) and has at least one phenolic hydroxyl group, as the phosphazene compound (H), and the photosensitive resin composition further includes a (meth)acrylic compound (L).

TECHNICAL FIELD

The present invention relates to a phosphazene compound, aphotosensitive resin composition, and usage thereof. More specifically,the present invention relates to (i) a phosphazene compound obtained byreacting a phenoxyphosphazene compound and/or a cross-linkedphenoxyphosphazene compound with an epoxy compound having an unsaturateddouble bond and/or an isocyanate compound, (ii) a photosensitive resincomposition which allows water system development, formation of afavorable pattern shape, and simplification of production steps,particularly, a photosensitive resin composition which uses phosphazeneflame retardants having a phenolic hydroxyl group and allows a curedresin film to have a superior flame retardancy, and (iii) usage thereof.

BACKGROUND ART

Recently, with rapid improvement in performances and functions and rapiddecrease in sizes and weights of electronic devices, electronic partsused in these electronic devices are required to have smaller sizes,lighter weights, and smaller thickness. Thus, on a print wiring boardwhich is to be provided with electronic parts, it is required to installa semiconductor or the like in a high density manner, to make wiresfiner, and it is required to make the print wiring board multi-layeredin order to reduce sizes and weights of the electronic parts and improvefunctions and performances of the electronic parts. In order to supportfiner wirings, it is necessary to use an insulative material having highelectric insulation property for protecting the wirings. Further, as theprint wiring substrate on which the electric parts are provided, aflexible print wiring board (referred to also as FPC as required) hasrecently attracted more attentions than an ordinary rigid print wiringboard, and has come to be further demanded. Further, a resin is used asa material for various products such as an electric product, anautomobile, and the like, due to its characteristics such as easiness tofabricate, mechanical property, electric property, appearance, and thelike.

Incidentally, in producing the print wiring board, a photosensitivematerial is used in various manners. That is, the photosensitivematerial is used in (i) formation of circuit patterned on the printwiring board (pattern circuit), (ii) formation of a protection layer forprotecting a surface and the pattern circuit of the print wiring board,(iii) formation of an insulation layer between layers in case where theprint wiring board has a plurality of layers, (iv) and the like. As thephotosensitive material used in these purposes, a liquid photosensitivematerial and a film photosensitive material are used. Among them, thefilm photosensitive material has such advantage that its film thicknessis evener and its workability is more excellent than the liquidphotosensitive material. Thus, various film photosensitive materials areused according to usages such as a pattern circuit resist film used toform a pattern circuit, a photosensitive cover lay film used to form theprotection layer, a photosensitive dry film resist used to form theinterlayer insulation layer, and the like.

For example, a polymer film referred to as a cover lay film is combinedwith a surface of the FPC so as to protect a conductive surface. As aprocess for combining the cover lay film with the conductor surface, itis general to perform the following process: The cover lay film,processed so as to have a predetermined shape, whose one side has anadhesive, is made to overlap the FPC and is properly positioned, andthen the cover lay film is thermally pressed against the FPC with apressing device or the like. However, as the foregoing adhesive, anepoxy adhesive or an acrylic adhesive is mainly used, but such adhesiveis inferior in soldering heat resistance, bonding strength at hightemperature, and flexibility. Thus, in case of combining the cover layfilm with the conductor surface with an adhesive, it is impossible tosufficiently make use of a performance of the polyimide film.

Further, in case of combining the cover lay film with the FPC with theconventional epoxy adhesives or acrylic adhesives, it is necessary toform a hole or a window on an uncombined cover lay film so as tocorrespond to a junction of a terminal or a part of the circuit.However, the cover lay film is thin, so that it is difficult to form ahole and the like. Furthermore, the hole and the like of the cover layfilm are almost manually positioned so as to correspond to junctions ofterminals or portions of the FPC. This is not preferable in terms ofworkability and positional accuracy, and the manufacturing costincreases.

In order to improve the workability and the positional accuracy,conventionally, (i) a method for forming a protection layer by applyinga photosensitive composition to the conductor surface and (ii) aphotosensitive cover lay film (the photosensitive dry film resist isused as a cover lay film) have been developed, thereby improving theworkability and the positional accuracy.

However, acrylic resins are used in the photosensitive cover lay film,so that its heat resistance property and durability of the film are notsufficient, and the film has no flame retardancy. That is, as thephotosensitive cover lay film and the photosensitive dry film resist(hereinafter, both of them are generically referred to as aphotosensitive dry film resist), merely acrylic or epoxy photosensitivedry film resists are focused at present, but there is such a problemthat the film having been cured is inferior in heat resistance, chemicalresistance, anti-bending property, and flame retardancy. In this way,the resin is more likely to burn than a metallic material or aninorganic material, so that improvement of the flame retardancy remainsunrealized.

A general method for realizing the flame retardancy is a method in whicha compound having a halogen is mixed. An example thereof is aphotosensitive dry film resist produced by curing a photosensitive resincomposition containing a bromic flame retardant (for example, PatentDocument 1). However, the photosensitive dry film resist recited inPatent Document 1 contains the bromic flame retardant, so that the flameretardant having a halogen may have a bad influence on the environment.Further, the flame retardant having a halogen gives a great load to theenvironment, so that study on non-halogenous (halogen-free) materials iscarried out all over the world. Thus, the halogen-free flame retardantis being studied instead of the bromic flame retardant (for example,Patent Documents 2, 3, and 4). As the halogen-free flame retardant,nitrogenous, phosphorus, and inorganic compounds, phosphate esterhydrate, red phosphorus hydrate, metal oxide hydrate, and the like, areknown. However, phosphate ester and red phosphorus are hydrolyzed whichmay results in occurrence of phosphoric acid, and they are likely todrop electric reliability. The metal oxide scatters and absorbs light,so that it is difficult to use the metal oxide as the photosensitiveresin.

Further, recently, a flame retardant using a resin to which a siliconecompound has been added has been being studied (for example, PatentDocument 5). Further, as a flame retardant, phosphazene compounds arebeing studied, and it is known that the phosphazene compounds exhibithigh flame retardant effect (for example, Patent Document 7). PatentDocument 7 discloses a flame retardant resin composition obtained byblending a phosphazene compounds with a polycarbonate resin and thelike. The phosphazene compounds have an excellent effect in improvingthe flame retardancy, and has such an advantage that the phosphazenecompounds give less load to the environment since this is a halogen-freeflame retardant.

Further, conventionally, polyimide resin materials which can be bondedat low temperature and in short time and are superior in heat resistancehave been proposed (for example, Patent Document 8). Further, aspolyimide adhesive materials favorably used in production of the FPC, amaterial having photosensitivity has been proposed (for example, PatentDocument 9). Also a laminate having not only flexibility but also heatresistance has been disclosed (for example, Patent Document 10).Incidentally, a resin material used in the wiring board is required tohave flame retardancy as described above, and various kinds of resinmaterials whose flame retardancy has been improved are proposed (forexample, Patent Document 11). Among them, it is more preferable to use aresin material having a phosphorus compound in order to avoid use of amaterial, giving some load to the environment, as much as possible.

[Patent Document 1]

Japanese Unexamined Patent Publication No. 335619/2001 (Tokukai2001-335619)(Publication date: Dec. 4, 2001)

[Patent Document 2]

Japanese Unexamined Patent Publication No. 235001/2002 (Tokukai2002-235001)(Publication date: Aug. 23, 2002)

[Patent Document 3]

Japanese Unexamined Patent Publication No. 19930/2001 (Tokukai2001-19930)(Publication date: Jan. 23, 2001)

[Patent Document 4]

Japanese Unexamined Patent Publication No. 49090/2001 (Tokukai2001-49090)(Publication date: Feb. 20, 2001)

[Patent Document 5]

Japanese Unexamined Patent Publication No. 40219/2001 (Tokukai2001-40219)(Publication date: Feb. 13, 2001)

[Patent Document 6]

Japanese Unexamined Patent Publication No. 40149/2001 (Tokukai2001-40149)(Publication date: Feb. 13, 2001)

[Patent Document 7]

Japanese Unexamined Patent Publication No. 181268/1999 (Tokukaihei11-181268)(Publication date: Jul. 6, 1999)

[Patent Document 8]

Japanese Unexamined Patent Publication No. 242820/1995 (Tokukaihei7-242820)(Publication date: Sep. 19, 1995)

[Patent Document 9]

Japanese Unexamined Patent Publication No. 27667/1994 (Tokukaihei6-27667)(Publication date: Feb. 4, 1994)

[Patent Document 10]

Japanese Unexamined Patent Publication No. 733/1998 (Tokukaihei10-733)(Publication date: Jan. 6, 1998)

[Patent Document 11]

Japanese Unexamined Patent Publication No. 335703/2001 (Tokukai2001-335703)(Publication date: Dec. 4, 2001)

However, in case of using the nitrogenous compound, the phosphoruscompound, or the inorganic compound as the halogen-free flame retardant,the nitrogenous compound generally has some influence on a curingproperty of the resin, and the phosphorus compound drops humidityresistance or has a similar influence, so that it is difficult topractically use each of these compounds. Thus, there are less choices offlame retardant materials which can be used in the photosensitive dryfilm resist required to have an electric insulation property andanti-hydrolysis property.

Further, also in case of using as the flame retardant the resin to whichthe silicone compound has been added, few kinds of resins can exhibitthe flame retardant effect. Further, the flame retardant to which thesilicone compound has been independently added rarely exhibits a greatflame retardant effect, and even the flame retardant whose effect can beconfirmed to some extent requires addition of a large quantity ofsilicone compounds in order to satisfy a strict flame retardantstandard. As a result, a bad influence is exerted onto other necessaryproperties of the resin, so that this results in disadvantage in cost.Thus, use of such flame retardant is not practical.

Further, even in case of using the phosphazene compound as the flameretardant, when a resin obtained by mixing a conventional phosphazenecompound is used in a cover lay film or the like, the phosphazenecompound is deposited (bled or juiced) on a surface of the resin, sothat properties of the resin drop. For example, conventionally usedpropoxylated phosphazene is in a liquid state, so that a bondingproperty of the photosensitive dry film resist cured after being treatedat high temperature significantly drops.

Further, the resin is used for resin parts used in electric andelectronic parts. In terms of environmental problems, solder containingno lead (lead-free solder) is practically used in a print wiring boardon which the resin parts are installed. In case of using the lead-freesolder, reflow temperature rises (250° C. to 260° C.), so that the resinparts are required to have sufficient heat resistance. However, in caseof using the resin obtained by mixing the conventional phosphazenecompound as the flame retardant, the phosphazene compound evaporates anddisappears at such high temperature. Thus, a flame retardant which morepersistently remains in the resin is required.

Further, a photo-curing resin which is cured by irradiation of an energyline such as an ultraviolet ray is practically used in various fieldsrepresented by a coating material field and an electric/electronicmaterial field instead of a conventional thermosetting resin. As acompound which gives flame retardancy to the resin, an acrylic compoundhaving a halogen and a compound having a double bond, e.g., a phosphateester compound which is likely to be hydrolyzed, are known. However,each of these compounds has such a problem that this exerts a great loadto the environment and such a problem that its hydrolysis property islow.

The present invention was made in view of the foregoing problems, and anobject of the present invention is to provide (i) a phosphazene compoundwhich allows water system development, formation of a favorable patternshape, and realization of not only properties such as heat resistance,hydrolysis property, easiness to process (inclusive of solventsolubility), and bonding property, but also photosensitivity, flameretardancy, and sufficient mechanical strength, the phosphazene compoundbeing favorably used to produce a wiring substrate for sufficientlysupporting reduction of a size and a weight of each electronic part ofan electronic device, and (ii) a photosensitive resin composition usingthe phosphazene compound, and (iii) typical usage thereof.

DISCLOSURE OF INVENTION

The inventors of the present invention diligently studied so as to solvethe foregoing problems. As a result of the study, they found itpreferable to use as a flame retardant a phosphazene compound obtainedby reacting a specific phenoxyphosphazene compound (A-1) and/or across-linked phenoxyphosphazene compound (A-2) with a specific epoxycompound (B) and/or an isocyanate compound (C), particularly, they foundit possible to realize excellent balance of flame retardancy,photosensitivity, and other properties in case of using the phosphazenecompound as a flame retardant of a photosensitive resin composition.

That is, a phosphazene compound according to the present invention isobtained by reacting a phenoxyphosphazene compound (A-1) having aphenolic hydroxyl group and/or a cross-linked phenoxyphosphazenecompound (A-2) obtained by cross-linking the phenoxyphosphazene compound(A-1) with an epoxy compound (B) having an unsaturated double bondand/or an isocyanate compound (C), wherein the phosphazene compound hasan unsaturated double bond in its molecule.

It is preferable to arrange the phosphazene compound so that thephenoxyphosphazene compound (A-1) is a circular phenoxyphosphazenecompound (A-11) represented by formula (1)

where m represents an integer ranging from 3 to 25, and each of R¹ andR² represents a phenyl group or a hydroxyphenyl group, and a singlemolecule has one or more hydroxyphenyl groups.

Further, it is preferable to arrange the phosphazene compound so thatthe phenoxyphosphazene compound (A-1) is a chain phenoxyphosphazenecompound (A-12) represented by formula (2)

where n represents an integer ranging from 3 to 10000, and each of R³and R⁴ represents a phenyl group or a hydroxyphenyl group, and a singlemolecule has one or more hydroxyphenyl groups, and R⁵ represents—N═P(OC₆H₅)₃, —N═P(OC₆H₅)₂(OC₆H₄OH), —N═P(OC₆H₅)(OC₆H₄OH)₂,—N═P(OC₆H₄OH)₃, —N═P(O)OC₆H₅, or —N═P(O)(OC₆H₄OH), and R⁶ represents—P(OC₆H₅)₄, —P(OC₆H₅)₃(OC₆H₄OH), —P(OC₆H₅)₂(OC₆H₄OH)₂,—P(OC₆H₅)(OC₆H₄OH)₃, —P(OC₆H₄OH)₄, —P(O)(OC₆H₅)₂, —P(O)(OC₆H₅)(OC₆H₄OH),or —P(O)(OC₆H₄OH)₂.

Further, it is preferable to arrange the phosphazene compound so thatthe cross-linked phenoxyphosphazene compound (A-2) is obtained bycross-linking the phenoxyphosphazene compound (A-1) on the basis of aphenylene cross-linking group having at least one of an o-phenylenegroup, a m-phenylene group, a p-phenylene group, and a bisphenylenegroup represented by formula (3)

where R⁷ represents —C(CH₃)₂—, —SO₂—, —S—, or —O—, and p represents 0 or1.

Further, it is preferable to arrange the phosphazene compound so thatthe cross-linked phenoxyphosphazene compound (A-2) is a phenylenecross-linked phenoxyphosphazene compound (A-3) in which the circularphenoxyphosphazene compound (A-11) and/or the chain phenoxyphosphazenecompound (A-12) is used as the phenoxyphosphazene compound, and thephenylene cross-linking group intervenes between two oxygen atomsobtained by desorbing a phenyl group and a hydroxyphenyl group from thephenoxyphosphazene compound (A-1) so that a ratio at which the phenylgroup and the hydroxyphenyl group are contained in the cross-linkedphenoxyphosphazene compound ranges from 50 to 99.9% with respect to atotal of a phenyl group and a hydroxyphenyl group of thephenoxyphosphazene compound, the phenylene cross-linkedphenoxyphosphazene compound (A-3) including at least one phenolichydroxyl group.

A photosensitive resin composition according to the present inventionincludes at least the phosphazene compound having any one of theforegoing arrangements and a soluble polyimide resin (D) which issoluble in an organic solvent. It is preferable to arrange thephotosensitive resin composition so that further includes aphotoreaction initiator (E-1). Further, a photosensitive resincomposition according to the present invention includes at least thephosphazene compound having any one of the foregoing arrangements and aphotoreaction initiator (E-1). It is preferable to arrange thephotosensitive resin composition so that further includes a compoundhaving a carbon-carbon double bond (E-4).

Further, it is preferable to arrange the photosensitive resincomposition so that 1 wt % or more of the soluble polyimide resin (D) isdissolved in at least one kind of an organic solvent selected fromdioxolane, dioxane, tetrahydrofuran, N,N-dimethylformamide,N,N-dimethylacetamide, and N-methyl-2-pyrrolidone at temperature rangingfrom room temperature to 100° C.

The usage of the photosensitive resin composition according to thepresent invention is not particularly limited, but an example thereof isa photosensitive resin film produced by using the photosensitive resincomposition. The photosensitive resin film can be used as a print wiringadhesive film, a photosensitive cover lay film, a print wiring boardinsulative protection film, or a print wiring board substrate.

As described above, the phosphazene compound according to the presentinvention is obtained by reacting a phenoxyphosphazene compound (A-1)having a phenolic hydroxyl group and/or a cross-linkedphenoxyphosphazene compound (A-2) obtained by cross-linking thephenoxyphosphazene compound (A-1) with an epoxy compound (B) having anunsaturated double bond and/or an isocyanate compound (C), wherein thephosphazene compound has an unsaturated double bond in its molecule.

Further, as described above, the photosensitive resin compositionaccording to the present invention includes at least the phosphazenecompound and a soluble polyimide resin (D) which is soluble in anorganic solvent. Alternatively, the photosensitive resin compositionaccording to the present invention includes at least the phosphazenecompound and a photoreaction initiator (E-1).

Therefore, the phosphazene compound and the photosensitive resincomposition including the phosphazene compound are excellent not only inthe heat resistance, the dielectric property, and the flame retardancy,but also the easiness to process since bonding can be carried out withthe photosensitive resin composition at temperature lower thantemperature at which bonding is carried out with a conventionalthermoplastic polyimide resin adhesive. Moreover, a specific polyimideresin is used, so that the photosensitive resin composition has morepreferable balance than a conventional polyimide/epoxy resin mixtureadhesive in properties such as the easiness to process, the heatresistance, and the dielectric property. Thus, the photosensitive resincomposition according to the present invention allows bonding at lowertemperature than that in a conventional one, and is excellent in theeasiness to process and the treatability, and can exhibit excellent heatresistance, dielectric property, and flame retardancy.

As a result, in case where the photosensitive resin compositionaccording to the present invention is formed in a solution state likevarnish, the photosensitive resin composition can be used as a resinchemical product such as an adhesive, a coating agent, or an ink.Further, in case where the photosensitive resin composition according tothe present invention is formed in a resin sheet or a resin film, thephotosensitive resin composition can be favorably used as a print wiringboard (FPC) adhesive sheet, a photosensitive cover lay film, a printwiring board insulative circuit protection film, or a print wiring boardsubstrate.

Further, as a result of diligent study on the foregoing problems, theinventors of the present invention found that: by selecting acombination of a specific polyimide resin (G), a specific phosphazenecompound (H), and a specific (meth)acrylic compound (I) as a componentof the photosensitive resin composition, it is possible to realizeexcellent balance of the flame retardancy and other properties. As aresult, they completed the present invention.

That is, a photosensitive resin composition according to the presentinvention has at least a polyimide resin (G) and a phosphazene compound(H), and the photosensitive resin composition includes: a solublepolyimide resin (G-1), which has a carboxyl group and/or a hydroxylgroup and is soluble in an organic solvent, as the polyimide resin (G);and a phenoxyphosphazene compound (H-1) having a phenolic hydroxyl groupand/or a cross-linked phenoxyphosphazene compound (H-2), which isobtained by cross-linking the phenoxyphosphazene compound (H-1) and hasat least one phenolic hydroxyl group, as the phosphazene compound (H),and the photosensitive resin composition further includes a(meth)acrylic compound (I).

It is preferable to arrange the photosensitive resin composition so thatthe phenoxyphosphazene compound (H-1) includes a circularphenoxyphosphazene compound (H-11) represented by formula (1)

where m represents an integer ranging from 3 to 30, and each of R1 andR2 represents a phenyl group or a hydroxyphenyl group, and a singlemolecule has one or more hydroxyphenyl groups.

Further, it is preferable to arrange the photosensitive resincomposition so that the phenoxyphosphazene compound (H-1) includes achain phenoxyphosphazene compound (H-12) represented by formula (2)

where n represents an integer ranging from 3 to 10000, and each of R³and R⁴ represents a phenyl group or a hydroxyphenyl group, and a singlemolecule has one or more hydroxyphenyl groups, and R⁵ represents—N═P(OC₆H₅)₃, —N═P(OC₆H₅)₂(OC₆H₄OH), —N═P(OC₆H₅)(OC₆H₄OH)₂,—N═P(OC₆H₄OH)₃, —N═P(O)OC₆H₅, or —N═P(O)(OC₆H₄OH), and R⁶ represents—P(OC₆H₅)₄, —P(OC₆H₅)₃(OC₆H₄OH), —P(OH₆H₅)₂(OC₆H₄OH)₂,—P(OC₆H₅)(OC₆H₄OH)₃, —P(OC₆H₄OH)₄, —P(O)(OC₆H₅)₂, —P(O)(OC₆H₅)(OC₆H₄OH),or —P(O)(OC₆H₄OH)₂.

It is preferable to arrange the photosensitive resin composition so thatthe cross-linked phenoxyphosphazene compound (H-2) is obtained bycross-linking the phenoxyphosphazene compound (H-1) on the basis of aphenylene cross-linking group having at least one of an o-phenylenegroup, a m-phenylene group, a p-phenylene group, and a bisphenylenegroup represented by formula (3)

where R⁷ represents —C(CH₃)₂—, —SO₂—, —S—, or —O—, and p represents 0 or1.

It is more preferable to arrange the photosensitive resin composition sothat the cross-linked phenoxyphosphazene compound (H-2) is a phenylenecross-linked phenoxyphosphazene compound (H-2 1) in which the circularphenoxyphosphazene compound (H-11) and/or the chain phenoxyphosphazenecompound (H-12) is used as the phenoxyphosphazene compound, and thephenylene cross-linking group intervenes between two oxygen atomsobtained by desorbing a phenyl group and a hydroxyphenyl group from thephenoxyphosphazene compound (H-1) so that a ratio at which the phenylgroup and the hydroxyphenyl group are contained in the cross-linkedphenoxyphosphazene compound ranges from 50 to 99.9% with respect to atotal of a phenyl group and a hydroxyphenyl group of thephenoxyphosphazene compound, said phenylene cross-linkedphenoxyphosphazene compound (H-21) including at least one phenolichydroxyl group.

It is preferable to arrange the photosensitive resin composition so thatthe soluble polyimide resin (G-1) has at least one kind of anunsaturated double bond selected from an acryl group, a methacryl group,a vinyl group, and an allyl group.

Further, it is preferable to arrange the photosensitive resincomposition so that an amount of the phosphazene compound (H) rangesfrom 1 to 100 parts by weight with respect to 100 parts by weightcorresponding to a total weight of the polyimide resins (G) and the(meth)acrylic compound (I).

The usage of the photosensitive resin composition according to thepresent invention is not particularly limited, but an example thereof isa photosensitive resin film produced by using the photosensitive resincomposition. In the photosensitive resin film, in case of using 1 wt %of sodium hydroxide whose temperature is 40° C. as a developer and usinga spray developing device as developing means, it is preferable thatdissolving time under a spray pressure of 0.85 MPa is 180 seconds orless. Further, the photosensitive resin composition according to thepresent invention can be used as a pattern circuit resist film, aphotosensitive cover lay film, or a photosensitive dry film resist.

As described above, the photosensitive resin composition according tothe present invention includes at least the soluble polyimide resin(G-1.) and the phenoxyphosphazene compound (H-1) or the cross-linkedphenoxyphosphazene compound (H-2), and includes the (meth)acryliccompound (I).

Therefore, the phosphazene compound arranged in the foregoing manner andthe photosensitive resin composition having the phosphazene compound areexcellent not only in the photosensitivity, the heat resistance, thedielectric property, and the flame retardancy, but also the easiness toprocess since bonding can be carried out with the photosensitive resincomposition at temperature lower than temperature at which bonding iscarried out with a conventional thermoplastic polyimide resin adhesive.Moreover, a specific polyimide resin is used, so that the photosensitiveresin composition has more preferable balance than a conventionalpolyimide/epoxy resin mixture adhesive in properties such as theeasiness to process, the heat resistance, and the dielectric property.Further, the photosensitive resin composition according to the presentinvention has an excellent developing property in a basic aqueoussolution. Thus, the photosensitive resin composition according to thepresent invention allows bonding at lower temperature than that in aconventional one, and is excellent in the easiness to process and thetreatability, and can exhibit excellent heat resistance, dielectricproperty, and flame retardancy.

As a result, in case where the photosensitive resin compositionaccording to the present invention is formed in a solution state likevarnish, the photosensitive resin composition can be used as a resinchemical product such as an adhesive, a coating agent, or an ink.Further, in case where the photosensitive resin composition according tothe present invention is formed in a photosensitive resin film, thephotosensitive resin composition can be favorably used as a patterncircuit resist film, a photosensitive cover lay film, or aphotosensitive dry film resist.

Further, as a result of diligent study on the foregoing problems, theinventors of the present invention found that: it is possible to achievea predetermined object by using (i) a photosensitive resin compositionincluding a soluble polyimide resin (K) having a carboxyl group and/or ahydroxyl group, a specific phenoxyphosphazene compound (L), and a(meth)acrylic compound (I) and (ii) a photosensitive dry film resistproduced by using the photosensitive resin composition. As a result,they completed the present invention.

That is, the present invention relates to a photosensitive resincomposition includes a soluble polyimide resin (K) having a carboxylgroup and/or a hydroxyl group, a phenoxyphosphazene compound (L), and a(meth)acrylic compound (M), and the phenoxyphosphazene compound (L)includes at least one of a circular phenoxyphosphazene compound (L-1)represented by formula (22) and a chain phenoxyphosphazene compound(L-2) represented by formula (23),

where a represents an integer ranging from 3 to 30,

where R²⁵ represents group-N═P(OPh)₃ or group-N═P(O)OPh, and R²⁶represents group-P(OPh)₄ or group-P(O)(OPh)₂, and b represents aninteger ranging from 3 to 10000, wherein the phenoxyphosphazene compound(L) includes a cross-linked phenoxyphosphazene compound (L-3) having astructure cross-linked by causing a cross-linking group having any oneof an o-phenylene group, an m-phenylene group, a p-phenylene group, anda bisphenylene group represented by formula (3) to intervene between twooxygen atoms obtained by desorbing a phenyl group,

where R⁷ represents —C(CH₃)₂—, —SO₂—, —S—, or —O—, and p represents 0 or1.

It is preferable to arrange the photosensitive resin composition so thata soluble polyimide resin serving as the component (K) has at least onekind of a carbon-carbon double bond selected from an acryl group, amethacryl group, a vinyl group, and an allyl group.

Further, it is preferable to arrange the photosensitive resincomposition so that an amount of the component (L) ranges from 1 to 100parts by weight with respect to 100 parts by weight corresponding to atotal weight of the components (K) and (L).

Further, the present invention relates to a photosensitive dry filmresist produced by using the photosensitive resin composition recited inany one of the foregoing arrangements.

It is preferable to arrange the photosensitive dry film resist so that:in case of using 1 wt % of sodium hydroxide whose temperature is 40° C.as a developer and using a spray developing device as developing means,dissolution time under a spray pressure of 0.85 MPa is 180 seconds orless.

Further, the present invention relates to a print wiring board using thephotosensitive dry film resist as an insulative protection layer.

Additional objects, features, and strengths of the present inventionwill be made clear by the description below. Further, the advantages ofthe present invention will be evident from the following explanation inreference to the drawings.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a schematic illustrating a comb-shape pattern used in Examplesof the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

The following will explain Embodiment 1 of the present invention. Notethat, the present invention is not limited to this.

(A) Phosphazene Compound

The phosphazene compound according to the present invention is acompound obtained by reacting a phenoxyphosphazene compound (A-1) havinga phenolic hydroxyl group, and/or a cross-linked phenoxyphosphazenecompound (A-2) obtained by cross-linking the phenoxyphosphazene compound(A-1), and/or an isocyanate compound (C), and the phosphazene compoundhas an unsaturated double bond in its molecule.

The phenoxyphosphazene compound (A-1) and/or the cross-linkedphenoxyphosphazene compound (A-2) are included, so that it is possibleto give flame retardancy without losing the heat resistance of theobtained photosensitive resin composition. Particularly, the phosphazenecompound used in the present invention has a phenolic hydroxyl group inits molecule, so that the phenolic hydroxyl group remarkably improvescompatibility with respect to the soluble polyimide resin. Thus, in theobtained photosensitive resin composition, it is possible to suppressdeposition (bleeding or juicing) of the flame retardant on the surface,thereby further improving the flame retardancy.

Moreover, the phenolic hydroxyl group is included in the molecule, sothat the phosphazene compound allows formation of a mesh structure byreacting particularly with an epoxy resin component (described later) incuring the photosensitive resin composition. Thus, efficient curing ispossible, thereby obtaining a cured product having excellent heatresistance. Further, it is also possible to improve alkaline solubilitycompared with the conventional phosphazene compound.

Note that, hereinafter, the phosphazene compound according to thepresent invention, that is, the phosphazene compound which is obtainedby reacting the phenoxyphosphazene compound (A-1), and/or thecross-linked phenoxyphosphazene compound (A-2), the epoxy compound (B),and/or the isocyanate compound (C) and has an unsaturated double bond inits molecule is referred to as a double bond phosphazene compound forease of description.

[Phenoxyphosphazene Compound (A-1)]

The phenoxyphosphazene compound (A-1) used in synthesis of the doublebond phosphazene compound according to the present invention is notparticularly limited as long as the phenolic hydroxyl group is included.Specifically, it is preferable to use at least one of a circularphenoxyphosphazene compound (A-11) and a chain phenoxyphosphazenecompound (A-12).

First, the circular phenoxyphosphazene compound (A-11) has a structurerepresented by the following formula (1)

where m represents an integer ranging from 3 to 25, and each of R¹ andR² represents a phenyl group or a hydroxyphenyl group (—C₆H₄OH), and asingle molecule has one or more hydroxyphenyl groups.

Next, the chain phenoxyphosphazene compound (A-12) has a structurerepresented by the following formula (2)

where n represents an integer ranging from 3 to 10000, and each of R³and R⁴ represents a phenyl group or a hydroxyphenyl group, and a singlemolecule has one or more hydroxyphenyl groups, and R⁵ represents—N═P(OC₆H₅)₃, —N═P(OC₆H₅)₂(OC₆H₄OH), —N═P(OC₆H₅)(OC₆H₄OH)₂,—N═P(OC₆H₄OH)₃, —N═P(O)OC₆H₅, or —N═P(O)(C₆H₄OH), and R⁶ represents—P(OC₆H₅)₄, —P(OC₆H₅)₃(OC₆H₄OH), —P(OC₆H₅)2(OC₆H₄OH)₂,—P(OC₆H₅)(OC₆H₄OH)₃, —P(OC₆H₄OH)₄, —P(O)(OC₆H₅)₂, —P(O)(OC₆H₅)(OC₆H₄OH),or —P(O)(OC₆H₄OH)₂.

Each of the circular phenoxyphosphazene compound (A-11) and the chainphenoxyphosphazene compound (A-12) has excellent compatibility withrespect to the soluble polyimide resin and the epoxy resin (describedlater), and allows the obtained photosensitive resin composition to haveexcellent heat resistance after being cured.

A production process of the circular phenoxyphosphazene compound (A-11)and the chain phenoxyphosphazene compound (A-12) is not particularlylimited, but specific examples of the production process are recited inthe following documents.

Document A: Engineering/Chemistry Magazine, Vol. 67, No. 9, p.1378(1964), Masaaki Yokoyama et al.

Document B: Engineering/Chemistry Magazine, Vol. 73, No. 6, p.1164(1970), Tomoya Okuhashi et al.

Document C: Japanese Unexamined Patent Publication No. 219190/1983(Tokukaisho 58-219190)

Document D: Alessandro Medici, et al., Macromolecules, Vol. 25, No. 10,p. 2569 (.1992)

Document E: Japanese Unexamined Patent Publication No. 145394/1979(Tokukaisho 54-145394)

Document F: Japanese Unexamined Patent Publication No. 145395/1979(Tokukaisho 54-145395)

For example, a compound in which one hydroxyl group of bivalent phenolis protected by a methyl group or a benzyl group (for ease ofdescription, the compound is referred to as a protected phenol compound)is synthesized as in 4-methoxyphenol, 4-(benzyloxy)phenol, etc., and analkaline metallic salt (e.g., lithium salt, sodium salt, potassium salt,and the like) of the compounds is obtained. The alkaline metallic salt(4-methoxyphenol alkaline metallic salt or 4-(benzyloxy)phenol alkalinemetallic salt) of the obtained protected phenol compound is reacted withphosphonitryl chloride recited in Documents E and F. Thereafter, theresultant is reacted with pyridine halogenoid hydracid salt ortribromoboron etc. so as to deprotect the methyl group or the benzylgroup, thereby carrying out conversion into the hydroxyl group. Thistreatment allows synthesis of the foregoing phenoxyphosphazene compound.

Further, as to the phenoxyphosphazene compound, in case of producing acompound having a phenoxy group partially substituted by a hydroxylgroup, alkaline metal of the protected phenol compound and/or alkalinemetallic salt of hydroxyalkylphenol are obtained, and alkaline metallicsalt of alcoholic or phenolic compound is used at the same time asreaction with phosphonitryl chloride.

It is preferable to use the phenoxyphosphazene compound (A-1) since itis possible to give not only flame retardancy and high soldering-heatresistance but also excellent electric insulation property to thephotosensitive resin film obtained by curing the photosensitive resincomposition without using any halogen compound.

[Example of Synthesis (Production) of phenoxyphosphazene compound (A-1)]

The following explains a specific example of synthesis (production) ofthe circular phenoxyphosphazene compound (A-11) and the chainphenoxyphosphazene compound (A-12).

First, at least one kind of a dichlorophosphazene compound selected froma circular dichlorophosphazene compound represented by the followingformula (4) and a straight chain or chain dichlorophosphazene compoundrepresented by the following formula (5) is used as a materialphosphazene compound

where m represents an integer ranging from 3 to 25

where X² represents —N═PCl₃ or —N═P(O)Cl, and Y² represents —PCl₄ or—P(O)Cl₂, and n represents an integer ranging from 3 to 10000.

Then, alkaline metallic phenolate represented by the following formula(6) or (7) is reacted with the compound represented by the formula (4)or (5). Note that, in alkaline metallic phenolate represented by theformula (7), a position of an alkyloxy group (methoxy group) is notparticularly limited.

where M represents alkaline metal.

Due to the reaction, it is possible to introduce the phenyl group andthe methoxyphenyl group into the structure represented by the formula(4) or (5). At this time, in the structure represented by the formula(4) or (5), it is necessary that at least one methoxyphenyl group isintroduced into a single molecule. In other words, in case of reactingthe compound represented by the formula (4) or (5) with the compoundsrepresented by the formulas (6) and (7), it is necessary to define areaction condition including an amount (molar ratio conversion) of thecompound of the formula (7) so that at least one methoxyphenyl group isintroduced into a single molecule. Note that, a detail reactioncondition is not particularly limited, but a known condition is adopted.

In the compound obtained through the foregoing reaction, the reactionwith pyridine halogenoid hydracid salt or tribromoboron etc. causes themethoxyphenyl group to be deprotected, thereby carrying out conversioninto a hydroxyl group. The operation results in the synthesis of thecircular phenoxyphosphazene compound (A-11) represented by the formula(1) and the chain phenoxyphosphazene compound (A-12) represented by theformula (2).

[Cross-linked phenoxyphosphazene Compound (A-2)]

As described above, the cross-linked phenoxyphosphazene compound (A-2)used in the synthesis of the double bond phosphazene compound accordingto the present invention has at least one phenolic hydroxyl group, andis a phosphazene compound obtained by cross-linking thephenoxyphosphazene compound (A-1). The cross-linked phenoxyphosphazenecompound (A-2) may be obtained in any manner as long as thephenoxyphosphazene compound (A-1) is cross-linked with a knowncross-linking group. However, it is preferable to cross-link thephenoxyphosphazene compound (A-1) with phenylene cross-linking groups.

The phenylene cross-linking groups are not particularly limited as longas each cross-linking group has a phenyl group in its structure.However, a specific example thereof is a cross-linking group having atleast any one of an o-phenylene group, an m-phenylene group, and ap-phenylene group,

or a bisphenylene group represented by the following formula (3)

where R⁷ represents —C(CH₃)₂—, —SO₂—, —S— or —O—, and p represents 0 or1.

In the present invention, in case of synthesizing (producing) thecross-linked phenoxyphosphazene compound, any compound corresponding tothe phenoxyphosphazene compound may be used, but it is preferable to usethe circular phenoxyphosphazene compound (A-11) and/or the chainphenoxyphosphazene compound (A-12).

Further, in case where (1) the circular phenoxyphosphazene compound(A-11) and/or the chain phenoxyphosphazene compound (A-12) are used asthe phenoxyphosphazene compound and (2) the phenylene cross-linkinggroups are used as the cross-linking group, when these conditions aresatisfied, it is preferable to define a cross-linking condition so as tosatisfy the following conditions (3) and (4).

That is, it is preferable that: (3) the phenylene cross-linking groupsintervene between two oxygen atoms obtained by desorbing a phenyl groupand a hydroxyphenyl group from the circular phenoxyphosphazene compound(A-11) and/or the chain phenoxyphosphazene compound (A-12), and (4) aratio at which the phenyl group and the hydroxyphenyl group are includedin the cross-linked phenoxyphosphazene compound ranges from 50 to 99.9%with respect to a total of a phenyl group and a hydroxyphenyl group ofthe foregoing phenoxyphosphazene compound.

When the cross-linked phenoxyphosphazene compound (A-2) satisfying theconditions (1) to (4) is used, it is possible to further improve theflame retardancy of the heat-resistance resin composition. Note that,the cross-linked phenoxyphosphazene compound satisfying the conditions(1) to (4) is referred to as phenylene cross-linked phenoxyphosphazenecompounds (A-3).

[Example of Synthesis (Production) of Cross-linked phenoxyphosphazeneCompound (A-2)]

A production process of the cross-linked phenoxyphosphazene compound(A-2) is not particularly limited, but an example of the synthesisprocess thereof is described as follows by taking the phenylenecross-linked phenoxyphosphazene compounds (A-3) as an example.

First, the dichlorophosphazene compound represented by the formula (4)or (5) is reacted with alkaline metallic phenolate. As the alkalinemetallic phenolate used at this time, not only the alkaline metallicphenolate represented by the formula (6) or (7) but also alkalinemetallic diphenolate represented by the following formula (8) or (9)

where M represents alkaline metal, and R⁷ represents —C(CH₃)₂—, —SO₂—,—S— or —O—, and p represents 0 or 1.

A compound obtained in this manner has a structure in which: amethoxyphenyl group (and a phenyl group) is introduced into thestructure represented by the formula (4) or (5), and the structurerepresented by the formula (4) or (5) is cross-linked by the alkalinemetallic diphenolate represented by the formula (8) or (9). Thereafter,due to reaction with pyridine halogenoid hydracid salt or tribromoboron,the methyl group or the benzyl group is deprotected, thereby carryingout conversion into a hydroxyl group. On this account, it is possible toobtain a compound obtained by cross-linking the phenoxyphosphazenecompound represented by the formula (1) and/or the formula (2) witharomatic diol, that is, it is possible to obtain the phenylenecross-linked phenoxyphosphazene compounds (A-3).

An amount of the phenoxyphosphazene compound (inclusive of thecross-linked resultant) blended is not particularly limited, but it ispreferable that the amount ranges from 0.1 to 50 wt % with respect to100 wt % (total weight) of the heat-resistance resin composition. Whenthe amount is less than 0.1 wt %, the flame retardant effect may drop.When the amount exceeds 50 wt %, the bonding property may drop or thedynamic property may drop.

[Epoxy Compound (B)]

The following explains the epoxy compound (B) having an unsaturateddouble bond used in the synthesis of the phosphazene compound accordingto the present invention.

Any material may be used as the epoxy compound (B) according to thepresent invention as long as the compound has an epoxy group and anunsaturated double bond in its molecule. However, specific examplesthereof include glycidyl methacrylate, glycidyl acrylate, allyl glycidylether, glycidyl vinyl ether, or a compound etc. represented by thefollowing formula (10). where r represents an integer ranging from 0 to40, and R.sup.8 represents H or a methyl group. These compounds may beindependently used, or a suitable combination of two or more kinds maybe used.

The following explains reaction between the phenoxyphosphazene compound(A-1) (the circular phenoxyphosphazene compound (A-11) having a phenolichydroxyl group and/or the chain phenoxyphosphazene compound (A-12)having a phenolic hydroxyl group) and the epoxy compound (B) having anunsaturated double bond, that is, the following explains synthesis(production) of a double-bond phosphazene compound according to thepresent invention.

First, the phenoxyphosphazene compound (A-1) and the epoxy compound (B)are dissolved in an organic solvent. Preferable examples of the organicsolvent include: aromatics such as benzene, toluene, and xylene; etherssuch as ether, tetrahydrofuran, and dioxane; N-substituted amides suchas N,N-dimethylformamide; and the like. These organic solvents may beindependently used, or a suitable combination of two or more kinds maybe used. Note that, in case where the phenoxyphosphazene compound (A-1)melts at reaction temperature, it is possible to carry out the synthesiswithout any solvent.

A solution obtained by dissolving the phenoxyphosphazene compound (A-1)and the epoxy compound (B) is reacted in the presence of tertiary aminesuch as pyridine triethylamine at temperature ranging from roomtemperature or higher to reflux temperature or lower of the solvent forone to 20 hours. Further, in case of using no solvent, the epoxycompound (B) is dissolved in the phenoxyphosphazene compound (A-1)having melted, the thus obtained solution is reacted at temperatureranging from room temperature or higher to reflux temperature or lowerof the phenoxyphosphazene compound (A-1). On this account, it ispossible to obtain the double-bond phosphazene compound according to thepresent invention. Note that, it is possible to add a known stabilizerat the time of reaction.

In the foregoing reaction, it may be so arranged that: a reaction amountof the phenoxyphosphazene compound (A-1) having a phenolic hydroxylgroup and the epoxy compound (B) having an unsaturated double bond isadjusted so as to react all the phenolic hydroxyl groups of thephenoxyphosphazene compound with the epoxy compound (B) having anunsaturated double bond. Further, in case of using the double-bondphosphazene compound according to the present invention as thephotosensitive resin composition, it may be so arranged that: aphosphazene compound in which a phenolic hydroxyl group is left withoutreacting all the phenolic hydroxyl groups of the phosphazene compoundwith the epoxy compound (B) having an unsaturated double bond so as toimprove the solubility in the alkaline aqueous solution serving as thedeveloper.

An amount of the epoxy compound (B) blended is not more than three timeslarger, more preferably 2.5 times larger than the phenolic hydroxylgroup of the phenoxyphosphazene compound (A-1) in terms of a molarratio. Further, a lower limit of the amount of the epoxy compound (B)blended may be determined depending on an amount of the unsaturateddouble bond introduced into the phosphazene compound. The amount of theunsaturated double bond introduced into the phosphazene compound ispreferably at least 1, more preferably 1.2 or more for each molecule ofthe phosphazene compound. Thus, it is preferable to add the epoxycompound (B) of 1 or more mol for each mol of the phosphazene compound,and it is more preferable to add the epoxy compound (B) of 1.2 or moremol for each mol of the phosphazene compound.

[Isocyanate Compound (C)]

The following explains the isocyanate compound (C) having an unsaturateddouble bond which is used to synthesize the double bond phosphazenecompound according to the present invention.

Any compound may be used as the isocyanate compound (C) according to thepresent invention as long as the compound has an isocyanate group and anunsaturated double bond in its molecule. Specific examples thereofinclude methacryloylisocyanate, acryloylisocyanate,methacryloylethylisocyanate, acryloylethylisocyanate,methacryloxyethylisocyanate, acryloxyethylisocyanate,vinyldimethylbenzylisocyanate, m-isopropenyl-α,α-dimethylbenzylisocyanate, 2-methacryloyloxyethylisocyanate, and thelike. These compounds may be independently used, or a suitablecombination of two or more kinds may be used.

The following describes how the phenoxyphosphazene compound (A-1) (thecircular phenoxyphosphazene compound (A-11) having a phenolic hydroxylgroup and/or the chain phenoxyphosphazene compound (A-12) having aphenolic hydroxyl group) is reacted with the isocyanate compound (C)having an unsaturated double bond, that is, the following describessynthesis (production) of the double bond phosphazene compound accordingto the present invention.

First, the phenoxyphosphazene compound (A-1) and the isocyanate compound(C) are dissolved in an organic solvent. As the organic solvent, it ispossible to use: N-substituted amides such as N,N-dimethylformamide,N,N-diethylformamide, N-methylformanilide, N-formylpiperidine,N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropanamide,N-methyl-α-pyrrolidone, N-methyl-α-piperidone, and N-methylcaprolactam;N-substituted ureas such as N-tetramethylurea, N-acetyl-α-pyrrolidone,N-acetyl-α-piperidone, and N-acetylcaprolactam; N-substituted thioureassuch as N-tetramethylthiourea; sulfoxides such as dimethylsulfoxide,tetramethylenesulfoxide, diethylsulfoxide, diisopropylsulfoxide,di-n-propylsulfoxide, diisobutylsulfoxide, and di-n-butylsulfoxide; andN-substituted phosphorylamides such as hexamethylphosphorylamide andhexaethylphosphorylamide; aromatics such as benzene, toluene, andxylene; ethers such as ether, tetrahydrofuran, and dioxane; and thelike. These organic solvents may be independently used, or a suitablecombination of two or more kinds may be used. Note that, in case ofmelting the phenoxyphosphazene compound (A-1) at reaction temperature,it is possible to carry out the operation without any solvent.

A solution obtained by dissolving the phenoxyphosphazene compound (A-1)and the isocyanate compound (C) is reacted at temperature ranging fromroom temperature or higher to reflux temperature or lower for one to 20hours. In case of carrying out the reaction without any solvent, theisocyanate compound (C) is dissolved in the melted phenoxyphosphazenecompound (A-1), and the thus obtained solution is reacted at temperatureranging from room temperature or higher to reflux temperature or lowerof the phenoxyphosphazene compound (A-1). In this manner, it is possibleto obtain the double bond phosphazene compound according to the presentinvention. Note that, at the time of the reaction, it is possible to adda known stabilizer.

It may be so arranged that: a reaction amount of the phenoxyphosphazenecompound (A-1) having a phenolic hydroxyl group and the isocanatecompound (C) having an unsaturated double bond is adjusted so as toreact all the phenolic hydroxyl groups of the phenoxyphosphazenecompound with the isocyanate compound having the unsaturated doublebond. Further, in case of using the phosphazene compound of the presentinvention as a photosensitive resin composition, it may be so arrangedthat: a phosphazene compound in which the phenolic hydroxyl groups areleft is obtained without reacting all the phenolic hydroxyl groups ofthe phosphazene compound with the isocyanate compound having theunsaturated double bond so as to improve the solubility in the alkalineaqueous solution serving as the developer.

An amount of the isocyanate compound (C) blended is not more than threetimes larger, more preferably 2.5 times larger than the phenolichydroxyl group of the phenoxyphosphazene compound (A-1) in terms of amolar ratio. Further, a lower limit of the amount of the isocyanatecompound (C) blended may be determined depending on an amount of theunsaturated double bond introduced into the phosphazene compound. Theamount of the unsaturated double bond introduced into the phosphazenecompound is preferably at least 1, more preferably 1.2 or more for eachmolecule of the phosphazene compound. Thus, it is preferable to add theisocyanate compound (C) of 1 or more mol for each mol of the phosphazenecompound, and it is more preferable to add the isocyanate compound (C)of 1.2 or more mol for each mol of the phosphazene compound.

In the foregoing example, the phenoxyphosphazene compound (A-1) and/orthe cross-linked phenoxyphosphazene compound (A-2) are reacted with theepoxy compound (B) or the isocyanate compound (C) in synthesizing thedouble bond phosphazene compound according to the present invention.However, the double bond phosphazene compound according to the presentinvention may be synthesized by reacting the phenoxyphosphazene compound(A-1) and/or the cross-linked phenoxyphosphazene compound (A-2) with theepoxy compound (B) and the isocyanate compound (C). A reaction conditionat this time is not particularly limited, and a suitable combination ofthe reaction conditions explained in [Isocyanate compound (C)] may beadopted.

Photosensitive Resin Composition (D)

The photosensitive resin composition according to the present embodimentincludes at least the double bond phosphazene compound and polyimideresins (E). Among them, a soluble polyimide resin (E-1) having acarboxyl group and/or a hydroxyl group and being soluble in an organicsolvent is used as the polyimide resins (E).

[Polyimide Resins (E)]

As the polyimide resins according to the present embodiment, at leastthe soluble polyimide resin (E-1) is used. The soluble polyimide resin(E-1) of the present invention is a resin having a carboxyl group and/ora hydroxyl group in its side chain and being soluble in an organicsolvent, and the term “soluble polyimide resin” is an expediential termused to describe such a polyimide resin.

[Soluble Polyimide Resin (E-1)]

As described above, the “solubility” of the soluble polyimide resin(E-1) means a condition under which the resin is soluble in the organicsolvent. More specifically, this condition is as follows: 1 wt % or moreof the resin is dissolved in at least one kind of an organic solventselected from dioxolane, dioxane, tetrahydrofuran,N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidoneat temperature ranging from room temperature to 100° C.

Any resin may be used as the soluble polyimide resin (E-1) as long asthe resin has an imide ring as a recurring unit in its structure.Specifically, not only polyimide (resin having only an imide ring:polyimide resin in a narrow sense) but also polyamidimide,polyesterimide, polyetherimide, maleimide, and the like each of whichhas a recurring unit other than the imide ring are used as the polyimideresin in a broad sense.

Here, the soluble polyimide resin (E-1) is generally produced by thefollowing two methods. In the first method, an acid dianhydridecomponent and a diamine component are used as monomer components servingas materials of the soluble polyimide resin (E-1), and the monomercomponents are reacted with each other so as to polymerize polyamideacid (polyamic acid), and the polyamide acid (polyamic acid) isimidized, thereby obtaining the soluble polyimide resin. In the secondmethod, an acid dianhydride component and an isocyanate component areused as monomer components serving as materials of the soluble polyimideresin (E-1), and these monomer components are reacted with each other,thereby obtaining the soluble polyimide resin.

Specific arrangement of the soluble polyimide resin (E-1) is notparticularly limited. However, in the present invention, an aciddianhydride having a specific structure described later, diamine, orisocianate are used as the monomer components, thereby obtaining asoluble polyimide resin (D) which is more favorable in producing thephotosensitive resin composition according to the present invention. Aproduction method of the soluble polyimide resin (E-1) will be describedlater.

Note that, in the first method, it is necessary to carry out imidizationin case of using polyamide acid, and it is necessary to expose theresultant at high temperature exceeding 250° C. for a long time, so thatportions other than a copper foil or polyimide may deteriorate. However,it is preferable to use the imidized resultant in the soluble polyimideresin (E-1) according to the present invention. In this case, there isno deterioration in the photosensitive resin composition.

<Acid Dianhydride Component>

In the soluble polyimide resin (E-1) favorably used in the presentinvention, the acid dianhydride component is not particularly limited aslong as acid dianhydride is used, but specific examples thereof include:aliphatic or alicyclic tetra carboxylate dianhydride such as2,2′-hexafluoropropyliden diphthalate dianhydride, 2,2-bis(4-hydroxyphenyl)propane dibenzoate-3,3′,4,4′-tetracarboxylate dianhydride, butanetetracarboxylate dianhydride, 1,2,3,4-cyclobutane tetracarboxylatedianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylatedianhydride, 1,2,3,4-cyclopentane tetracarboxylate dianhydride,2,3,5-tricarboxycyclopentyl acetic acid dianhydride,3,5,6-tricarboxynorbornane-2-acetic acid dianhydride,2,3,4,5-tetrahydrofuran tetracarboxylate dianhydride,5-(2,5-dioxotetrahydrofural)-3-methyl-3-cyclohexane-1, 2-dicarboxylatedianhydride, and bicyclo[2,2,2]-octo-7-ene-2,3,5,6-tetracarboxylatedianhydride; and aromatic tetracarboxylate dianhydride such aspyromellitic acid dianhydride, 3,3′,4,4′-benzophenone tetracarboxylatedianhydride, 3,3′,4,4′-biphenylsulfone tetracarboxylate dianhydride,1,4,5,8-naphthalene tetracarboxylate dianhydride, 2,3,6,7-naphthalenetetracarboxylate dianhydride, 3,3′,4,4′-biphenylether tetracarboxylatedianhydride, 3,3′,4,4′-dimethyldiphenylsilane tetracarboxylatedianhydride, 3,3′,4,4′-tetraphenylsilane tetracarboxylate dianhydride,1,2,3,4-furan tetracarboxylate dianhydride,4,4′-bis(3,4-dicarboxyphenoxy)diphenylsulfide dianhydride,4,4′-bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride,4,4′-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride,4,4′-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride,3,3′,4,4′-perfluoroisopropyliden diphthalic acid dianhydride,3,3′,4,4′-biphenyltetracarboxylate dianhydride, bis(phthalicacid)phenylphosphinoxide dianhydride, p-phenylene-bis(triphenyl phthalicacid)dianhydride, m-phenylene-bis(triphenyl phthalic acid)dianhydride,bis(triphenyl phthalic acid)-4,4′-diphenylether dianhydride, andbis(triphenyl phthalic acid)-4,4′-diphenylmethane dianhydride; and thelike. These tetracarboxylate dianhydrides may be independently used, ora suitable combination of two or more kinds may be used.

Particularly, it is preferable to select one of structures representedby the following formulas (11) and (12) in order to express the heatresistance and the mechanical property at a high level.

where R⁹ represents an ester bond or an ether bond, and R¹⁰ represents abinary organic group.

Particularly, it is preferable to use an acid dianhydride having astructure selected from the followings (13).

where R¹² represents hydrogen, halogen, a methoxy or an alkyl groupcontaining 1 to 16 carbon atoms. Further, R¹¹ represents —O—, —CH₂—,—(C═O)—, —C(CH₃)₂—, —C(CF₃)₂—, or —SO₂—.

In order to obtain the soluble polyimide resin whose solubility in theorganic solvent is high, it is preferable to use, in the compoundrepresented by the formula (11) or (12), parts of2,2′-hexafluoropropyliden diphthalic acid dianhydride,2,3,3′,4′-biphenyltetracarboxylate dianhydride,4,4-(4,4′-isopropylidendiphenoxy)bisphthalic acid,2,2-bis(4-hydroxyphenyl)propandibenzoate-3,3′,4,4′-tetracarboxylatedianhydride.

<Diamine Component>

In the soluble polyimide resin (E-1) favorably used in the presentinvention, the diamine component used as a material is not particularlylimited as long as diamine is used. However, as the developer used todevelop the photosensitive resin, an aqueous solution, particularly, analkaline aqueous solution developer comes to be used instead of anorganic solvent developer since the organic solvent developer has someinfluence on the environment. Thus, in the present embodiment, in orderto carry out the development with the alkaline aqueous solution, it ispreferable to use diamine having one or two carboxyl groups or one ortwo hydroxyl groups in its molecule (for ease of description, thisdiamine is referred to as hydroxydiamine) as the diamine componentconstituting the soluble polyimide resin. On this account, it ispossible to obtain the soluble polyimide resin having a carboxyl groupor a hydroxyl group, thereby carrying out the development with thealkaline aqueous solution.

As the hydroxydiamine, any diamine may be used as long as the diaminehas two carboxyl groups. However, specific examples thereof include:diamino phthalic acids such as 2,5-diamino terephthalic acid; carboxybiphenyl compounds such as 3,3′-diamino-4,4′-dicarboxy biphenyl,3,3′-diamino-4,4′-dicarboxybiphenyl,4,4′-diamino-3,3′-dicarboxybiphenyl,4,4′-diamino-2,2′-dicarboxybiphenyl, and4,4′-diamino-2,2′,5,5′-tetradicarboxybiphenyl; carboxy diphenylalkanessuch as carboxydiphenylmethane such as3,3′-diamino-4,4′-dicarboxydiphenylmethane,2,2-bis[3-amino-4-carboxyphenyl]propane,2,2-bis[4-amino-3-carboxyphenyl]propane,2,2-bis[3-amino-4-carboxyphenyl]hexafluoropropane, and4,4′-diamino-2,2′,5,5′-tetracarboxydiphenylmethane; carboxydiphenylethercompound such as 3,3′-diamino-4,4′-dicarboxydiphenylether,4,4′-diamino-3,3′-dicarboxydiphenylether,4,4′-diamino-2,2′-dicarboxydiphenylether, and4,4′-diamino-2,2′,5,5′-tetracarboxydiphenylether; diphenyl sulfonecompound such as 3,3′-diamino-4,4′-dicarboxydiphenylsulfone,4,4′-diamino-3,3′-dicarboxydiphenylsulfone,4,4′-diamino-2,2′-dicarboxydiphenylsulfone, and4,4′-diamino-2,2′,5,5′-tetracarboxydiphenylsulfone; bis[(carboxyphenoxy)phenyl]alkane compounds such as2,2-bis[4-(4-amino-3-carboxyphenoxy)phenyl]propane; bis[(carboxyphenoxy)phenyl]sulfone compound such as2,2-bis[4-(4-amino-3-carboxyphenoxy)phenyl]sulfone; and the like. Thesediamines each of which has two carboxyl groups may be independentlyused, or a suitable combination of two or more kinds may be used.

Further, it is preferable that a COOH equivalent (carboxylic acidequivalent) of the soluble polyimide resin (E-1) of the presentinvention ranges from 300 to 3000. This is realized by using the diaminehaving a carboxyl group as a material for the soluble polyimide resin(E-1). A carboxylic acid equivalent of the soluble polyimide resin (E-1)preferably ranges from 350 to 2500, more preferably from 350 to 2000. Itis not preferable that the carboxylic acid equivalent exceeds 3000 sinceit is difficult to dissolve the polyimide in the aqueous solutionalkaline developer and it takes longer time to carry out the developmentunder this condition. Note that, the carboxylic acid equivalent means anaverage molecular weight for each carboxylic acid. For example, when 5millimole of carboxylic acid is included in 1 g, the carboxylic acidequivalent is 200. Further, for example, in a resin having 1000recurring units, when two carboxylic acids are included in eachrecurring unit, the carboxylic acid equivalent is 500.

Note that, in case where diamine having two or more carboxyl groups isused, it is possible to realize the carboxylic acid equivalent of 300 orless. However, it is necessary to use a monomer whose molecular weightis large to some extent in order to realize a structure having highsolubility, so that it is preferable that the carboxylic acid equivalentis 300 or more.

In order to realize the favorable carboxylic acid equivalent, it ispreferable to use diamine having two or more carboxyl groups in itsmolecule. When the diamine is used, it is possible to realize apredetermined carboxylic acid equivalent even in case where another kindof diamine is copolymerized, and it is easier to design properties, sothat this arrangement is preferable. When the aforementioned carboxylicacid equivalent is satisfied, it is possible to use also diamine, suchas 3,5-diamino benzoic acid, having one carboxyl group.

Further, the hydroxydiamine is not particularly limited as long asdiamine has two hydroxyl groups. However, specific examples thereofinclude: hydroxybiphenyl compounds such as 4,6-diaminoresorcinol,3,3′-diamino-4,4′-dihydroxybiphenyl,4,4′-diamino-3,3′-dihydroxybiphenyl,4,4′-diamino-2,2′-dihydroxybiphenyl, and4,4′-diamino-2,2′,5,5′-tetrahydroxybiphenyl; hydroxyl diphenylalkanessuch as hydroxydiphenylmethane such as3,3′-diamino-4,4′-dihydroxydiphenylmethane,4,4′-diamino-3,3′-dihydroxydiphenylmethane,4,4′-diamino-2,2′-dihydroxydiphenylmethane, 2,2-bis[3-amino-4-hydroxyphenyl]propane, 2,2-bis[4-amino-3-hydroxy phenyl]propane,2,2-bis[3-amino-4-hydroxy phenyl]hexafluoropropane, and4,4′-diamino-2,2′,5,5′-tetrahydroxydiphenylmethane; hydroxydiphenylether compounds such as 3,3′-diamino-4,4′-hydroxy diphenylether,4,4′-diamino-3,3′-dihydroxydiphenylether,4,4′-diamino-2,2′-dihydroxydiphenylether, and 4,4′-diamino-2,2′,5,5′-tetrahydroxydiphenylether; diphenylsulfone compounds such as3,3′-diamino-4,4′-dihydroxydiphenylsulfone,4,4′-diamino-3,3′-dihydroxydiphenylsulfone,4,4′-diamino-2,2′-dihydroxydiphenylsulfone, and4,4′-diamino-2,2′,5,5′-tetrahydroxydiphenylsulfone; bis[(hydroxyphenoxy)biphenyl]alkane compounds such as2,2-bis[4-(4-amino-3-hydroxyphenoxy)phenyl]propane;bis(hydroxyphenoxy)biphenyl compounds such as4,4′-bis(4-amino-3-hydroxyphenoxy)biphenyl;bis[(hydroxyphenoxy)phenyl]sulfone compounds such as 2,2-bis[4-(4-amino-3-hydroxyphenoxy)phenyl]sulfone; bis(hydroxyphenoxy)biphenylcompounds such as 4,4′-diamino-3,3′-dihydroxydiphenylmethane,4,4′-diamino-2,2′-dihydroxydiphenylmethane,2,2-bis[3-amino-4-hydroxyphenyl]propane, and4,4′-bis(4-amino-3-hydroxyphenoxy)biphenyl; and the like. These diamineseach of which has two hydroxyl groups may be independently used, or asuitable combination of two or more kinds may be used.

Further, it is possible to use also diamine having one hydroxyl group asthe hydroxydiamine. Specific examples thereof include diaminophenolssuch as 2,4-diaminophenol and the like.

Further, an OH equivalent (hydroxyl group equivalent) of the solublepolyimide resin (E-1) of the present invention preferably ranges from250 to 3000, more preferably from 300 to 2000, most preferably from 300to 1500. It is not preferable that the hydroxyl group equivalent exceeds3000 since it is difficult to dissolve the resin in the alkaline aqueoussolution and it is difficult to carry out the development. Further, itis not preferable that the hydroxyl group equivalent is less than 250since the heat resistance drops and the resin is likely to absorb themoisture due to a large amount of water-absorptive hydroxyl groups. Notethat, the hydroxyl group equivalent is an average molecular weight foreach hydroxyl group. For example, when 5 millimole of hydroxyl groupsare included in 1 g, the hydroxyl group equivalent is 200. Further, forexample, in a resin having 1000 recurring units, when two hydroxylgroups are included in each recurring unit, the hydroxyl groupequivalent is 500.

Further, there is a case where it is preferable to use not only thehydroxydiamine but also diamine having a siloxane bond (—Si—O—) (forease of description, this diamine is referred to as siloxanediamine) asthe diamine component constituting the soluble polyimide resin (E-1). Aspecific example of the siloxanediamine is a compound represented by thefollowing formula (14)

where R¹³ represents an alkyl group containing 1 to 12 carbon atoms, ora phenyl group, and y represents an integer ranging from 1 to 40, and zrepresents an integer ranging from 1 to 20. When the siloxanediamine isused, it is possible to improve the solubility of the thus obtainedsoluble polyimide resin (E-1) in the organic solvent. Further, it ispreferable to use the siloxanediamine represented by the formula (14)since it is possible to obtain the soluble polyimide resin having highflexibility and high solubility.

In the formula (14), favorable examples of R¹³ are a methyl group, anethyl group, and a phenyl group. A particularly preferable one is themethyl group. Further, it is more preferable that z is an integerranging from 2 to 10, and it is particularly preferable that z is aninteger ranging from 2 to 5. It is more preferable that y is an integerranging from 4 to 30, and it is further more preferable that y is aninteger ranging from 5 to 20, and it is particularly preferable that yis an integer ranging from 8 to 15. As to the range of y, its influenceon properties of the soluble polyimide resin is great. When y is a smallvalue, the obtained soluble polyimide resin is likely to be lessflexible, and when y is excessively large, the obtained solublepolyimide resin is likely to have less heat resistance. Further, in allthe diamine components, a molar ratio of the siloxanediamine preferablyranges from 5 to 70 mol %, more preferably from 10 to 50 mol %.

Further, any material may be used to constitute the soluble polyimideresin (E-1) as long as the material is diamine, and diamine other thanthe hydroxydiamine and the siloxanediamine may be used. Specificexamples of other diamine include: aromatic diamine such as p-phenylenediamine, m-phenylene diamine, 4,4′-diamino diphenylmethane,4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl ether,4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone,1,5-diaminonaphthalene, 3,3-dimethyl-4,4′-diamino biphenyl,5-amino-1-(4′-aminophenyl)-1, 3,3-trimethyl indan, 6-amino-1-(4′-aminophenyl)-1,3,3-trimethyl indan, 4,4′-diaminobenzanilide,3,5-diamino-3′-trifluoromethyl benzanilide,3,5-diamino-4′-trifluoromethyl benzanilide, 3,4′-diamino diphenylether,2,7-diamino fluorene, 2,2-bis(4-aminophenyl)hexafluoropropane,4,4′-methylene-bis(2-chloro aniline), 2,2′,5,5′-tetrachloro-4,4′-diamino biphenyl, 2,2′-dichloro-4,4′-diamino-5,5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diamino biphenyl,4,4′-diamino-2,2′-bis(trifluoromethyl)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(4-amino phenoxy)benzene,4,4′-bis(4-amino phenoxy)-biphenyl, 1,3′-bis(4-amino phenoxy)benzene,9,9-bis(4-amino phenyl)fluorene, 4,4′-(p-phenyleneisopropyliden)bisaniline, 4,4′-(m-phenylene isopropyliden)bisaniline,2,2′-bis[4-(4-amino-2-trifluoromethyl phenoxy)phenyl]hexafluoropropane,and 4,4′-bis[4-(4-amino-2 -trifluoromethyl)phenoxy]-octafluorobiphenyl;aromatic diamine having (i) two amino groups coupled to an aromatic ringsuch as diaminotetraphenylthiophene and (ii) a hetero atom other than anitrogen atom of each amino group; aliphatic diamine such as1,1-methaxylylene diamine, 1,3-propanediamine, tetramethylene diamine,pentamethylene diamine, octamethylene diamine, nanomethylene diamine,4,4-diamino heptamethylene diamine, 1.4-diamino cyclohexane, isophoronediamine, tetrahydro dicyclopentadienylene diamine,hexahydro-4,7-methanoindanylene dimethylene diamine, tricyclo[6,2,1,02.7]-undecylene dimethyl diamine, and4,4′-methylenebis(cyclohexylamine); and the like. These diamines may beindependently used, or a suitable combination of two or more kinds maybe used.

In case of using the aromatic diamine, it is advantageous, in designingthe photosensitive resin composition, to use diamine having an aminogroup in an m-position (3-) since the soluble polyimide resin itself islikely to less absorb light at g-line and i-line areas.

<Synthesis of Soluble Polyimide Resin (E-1)>

The soluble polyimide resin (E-1) used in the present invention can beproduced in accordance with a known method. Specifically, the synthesismethod (production method) of the soluble polyimide resin (E-1) isroughly divided into two methods depending on materials used.

In the first method, an acid dianhydride component and a diaminecomponent are used as materials (monomers), and these monomer componentsare condensed so as to synthesize polyamide acid (polyamic acid) servingas a precursor, and these resultants are chemically or thermallysubjected to dehydration cyclization (imidization). In this manner, thefirst method is a two-step method. While, in the second method, an aciddianhydride component and an isocyanate component are used as materials,and these monomer components are polymerized, thereby obtaining thepolyimide resin. In this manner, the second method is a single-stepmethod.

The following description details the first method in which synthesis(production) of polyamide acid and imidization of the polyamide acid arecarried out and details the second method.

<Synthesis (Production) Method of Polyamide Acid in the First Method>

The synthesis (production) method of polyamide acid is a method in whichan acid dianhydride component containing at least one kind of aciddianhydride is reacted with a diamine component containing at least onekind of diamine in an organic solvent. At this time, the aciddianhydride component and the diamine component are blended with eachother so that they are substantially identical with each other in amolar ratio. Thus, in case of using only one kind of acid dianhydrideand only one kind of diamine, it is necessary only to blend them so thatthey are substantially identical with each other in a molar ratio. Incase of two or more kinds of acid dianhydrides and two or more kinds ofdiamines, it is necessary only to blend them so that a total amount ofthe acid dianhydride components (total amount of plural aciddianhydrides) and a total amount of the diamine components (total amountof plural diamines) are substantially identical with each other in amolar ratio. In case of using plural acid dianhydrides and pluraldiamines, it is possible to intentionally obtain a polyamide acidcopolymer.

In the synthesis of the polyamide acid, the method for reacting themonomer components is not particularly limited, but it is general that:after dissolving in the organic solvent the acid dianhydride componentand the diamine component which are substantially identical with eachother in a molar ratio, the resultant is stirred until completion ofpolymerization while controlling various reaction conditions. Accordingto the method, it is possible to obtain a solution through dissolutionof the polyamide acid in the organic solvent (hereinafter, the solutionis referred to as a polyamide acid solution).

An example of an order in which the acid dianhydride component and thediamine component are added is as follows: (1) the diamine component isdissolved in the organic solvent and then the acid dianhydride componentis added thereto; (2) the acid dianhydride component is dissolved in theorganic solvent and then the diamine component is added thereto; and (3)a proper amount of diamine component is added to and dissolved in theorganic solvent, and the acid dianhydride component whose amount exceedsthe amount of the diamine component is added thereto, and a diaminecomponent whose amount corresponds to the excess of the added aciddianhydride is added thereto; and so on. However, the order is notparticularly limited. Note that, “dissolve” means not only a conditionunder which a solvent completely dissolves a substance but also acondition under which the substance is evenly dispersed or diffused inthe solvent so as to be substantially dissolved in the solvent.

A synthesis condition in the synthesis reaction of the polyamide acid isnot particularly limited as long as polymerization of the monomercomponents sufficiently enables synthesis of the polyamide acid. In thepresent invention, as to the synthesis conditions, it is preferable todefine a temperature condition, a reaction time, and an organic solventto be used, as follows.

First, the temperature condition under which synthesis reaction of thepolyamide acid is carried out is not particularly limited as long as thetemperature range allows polymerization of the acid dianhydridecomponent and the diamine component. However, an upper limit of thetemperature is preferably 80° C. or lower, more preferably 50° C. orlower, further more preferably 30° C. or lower, particularly preferably20° C. or lower. Further, a lower limit of the temperature is preferably−20° C. or more. When the temperature exceeds 80° C., the polyamide acidmay be decomposed. When the temperature is lower than −20° C., thepolymerization reaction is more slowly promoted.

Next, the reaction time in the synthesis reaction of the polyamide acidis not particularly limited as long as it is possible to complete thepolymerization reaction of the acid dianhydride component and thediamine component within this time. However, generally, 50 hours isenough as an upper limit of the reaction time, and the upper limit maybe 12 hours or less. While, a lower limit of the reaction time ispreferably 30 minutes or more, and more preferably 3 hours or more.

Next, the organic solvent used in the synthesis reaction of thepolyamide acid is not particularly limited as long as the solvent cansufficiently dissolve the polyamide acid, but it is general to use anorganic polar solvent. Further, it is preferable to select an organicpolar solvent which can favorably dissolve the polyamide acid and whoseboiling point is as low as possible, in order to make it easier to stirthe solvent while suppressing increase of viscosity in synthesizing thepolyamide acid, to make it easier to dry the obtained soluble polyimideresin (E-1), and to realize a similar object. Thus, it is possible tomake the production steps of the soluble polyimide resin (E-1) moreefficient.

Specific examples of the organic polar solvent used in the synthesis ofthe polyamide acid include: sulfoxide solvent such as N,N-dimethylsulfoxide and N,N-diethyl sulfoxide; formamide solvent such asN,N-dimethyl formamide and N,N-diethyl formamide; acetamide solvent suchas N,N-dimethyl acetamide and N,N-diethyl acetamide; pyrrolidone solventsuch as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone; phenol solventsuch as phenol, o-cresol, m-cresol, p-cresol, xylenol, phenol halide,and catechol; ether solvent such as tetrahydrofuran and dioxane; alcoholsolvent such as methanol, ethanol, and butanol; cellosolve such as butylcellosolve; hexamethylphosphoamide; γ-butyrolactone; and the like, butthe organic polar solvent is not particularly limited.

These organic polar solvents may be independently used, or a combinationof two or more kinds may be used as a mixture. Further, a combination ofthe organic polar solvent and an aromatic carbon hydride such as xyleneor toluene may be used as required.

A specific condition of the polyamide acid solution obtained in theforegoing synthesis method is not particularly limited, it is preferablethat logarithmic viscosity is within the following range. That is, incase where 100 ml of a solution is prepared by using the polyamide acidso that its concentration is 0.5 g/N-methyl-2-pyrrolidone, thelogarithmic viscosity at 30° C. preferably ranges from 0.2 to 4.0(deciliter/gram), more preferably from 0.3 to 2.0 (deciliter/gram).

The polyamide acid used in the present invention is obtained by reactingthe acid dianhydride component and the diamine component with each otherin the organic solvent as described above. This reaction can be carriedout as follows: the diamine component is dissolved or dispersed in theorganic solvent in a slurry manner in an inert atmosphere such as argonor nitrogen, and then the acid dianhydride is added. The aciddianhydride is dissolved in the organic solvent or is diffused in aslurry manner or the acid dianhydride is in a solid state. In this case,the reaction temperature preferably ranges from −20° C. to 90° C., andthe reaction time preferably ranges from 30 minutes to 24 hours.

Further, an average molecular weight of the polyamide acid used in thepresent invention preferably ranges from 5000 to 1000000. When theaverage molecular weight is less than 5000, also a molecular weight ofthe obtained polyimide composition drops. Thus, even when the polyimidecomposition is used as a resin, the resin is likely to be brittle.While, the average molecular weight exceeds 1000000, viscosity of thepolyamide acid varnish is too high, so that it is likely to be difficultto treat the polyimide acid varnish. Further, it is also possible to mixvarious kinds of organic additives, inorganic fillers, or various kindsof reinforcing agents with the polyimide composition.

<Imidization of Polyamide Acid in the First Method>

The soluble polyimide resin (E-1) used in the present invention isobtained by imidizing the polyamide acid produced in the foregoingsynthesis method. A specific means for carrying out the imidization isnot particularly limited. However, the polyamide acid in the polyamideacid solution is subjected to dehydration ring closure for examplethrough a thermal process or a chemical process. The thermal process isa process in which the polyamide acid solution is dehydrated throughthermal treatment. The chemical process is a process in which thedehydration is carried out with a dehydrating agent. In addition tothese techniques, there is a process in which the imidization is carriedout through heat treatment under reduced pressure.

(1) Thermal Process

The thermal process is not particularly limited as long as ring closurebased on dehydration is carried out by heating the polyamide acid.Specifically, it is also possible to carry out the ring closure based ondehydration with respect to the polyamide acid for example by performingsuch an operation that: the polyamide acid solution is heated so as topromote imidization reaction and the solvent is evaporated at the sametime; or a similar operation. Conditions of the heat treatment are notparticularly limited, but it is preferable that the heating temperatureis 300° C. or lower and the heating time ranges from 5 minutes to 10hours. An example of the thermal process is an azeotropy process usingan azeotropic agent. Further, it is possible to adopt a thermalcyclization process or the like using toluene, xylene, or the like.

In the azeotropy process using the azeotropic agent, the imidization iscarried out as follows: water such as toluene, xylene, or the like andazeotropic solvent are added to the polyamide acid solution, andtemperature of the resultant is raised at 170° C. to 200° C., andreaction thereof is carried out for 1 to 5 hours while positivelyexcluding water, generated by dehydration ring closure of the polyamideacid, to the outside of the system. After completion of the reaction, aproduct is deposited in an alcohol solvent such as methanol, and theproduct is rinsed with an alcohol solvent as required, and then therinsed product is dried, thereby obtaining a soluble polyimide resin(G-1).

Further, another method for carrying out the imidization based on thethermal process is as follows: the polyamide acid solution is made toflow in a spreading manner on or is applied to a film-shape support suchas a glass plate, a metal plate, a PET (polyethylene terephthalate), andthe like, and then the film-shape support is heated at a temperatureranging from 80° C. to 300° C., thereby obtaining the soluble polyimideresin (G-1).

Note that, the heating time varies depending on an amount of thepolyamide acid solution to be subjected to the dehydration ring closureand temperature at which the polyamide acid solution is heated.Generally, it is preferable to heat the polyamide acid solution for aperiod of time ranging from one minute to five hours after the processtemperature has reached the maximum temperature. By carrying out thethermal process, it is possible to obtain the soluble polyimide resin(E-1).

(2) Chemical Process

An example of the chemical process is a process in which a dehydratingagent whose amount is not less than a stoichiometric amount and acatalyst are added to the polyamide acid solution, thereby carrying outdehydration reaction and evaporation of the organic solvent. Aftercompletion of the reaction, a product is deposited in an alcohol solventsuch as methanol, and the deposited product is rinsed with an alcoholsolvent as required, and then the rinsed product is dried. By carryingout the chemical process, it is possible to obtain the soluble polyimideresin (E-1).

Specific examples of the dehydrating agent include: fatty acid anhydridesuch as acetic anhydride and propionic acid anhydride; aromatic acidanhydride such as anhydrous benzoic acid; carbodiimides such asN,N′-dichlohexylcarbodiimide and N,N′-diisopropylcarbodiimide; and thelike. Further, specific examples of the catalyst include: aliphatictertiary amines such as triethylamine and trimethylamine; aromatictertiary amines such as dimethylaniline; heterocyclic tertiary aminessuch as pyridine, α-picoline, β-picoline, γ-picoline, isoquinoline, andimidazole.

Conditions of the chemical process are not particularly limited, but thereaction temperature is preferably 100° C. or lower, and the reactiontime preferably ranges from approximately one to 50 hours. Further,conditions of the evaporation of the organic solvent are notparticularly limited, the heating temperature is preferably 200° C. orlower, and the heating time preferably ranges from approximately 5minutes to 12 hours.

Note that, in case where the soluble polyimide resin (G-1) obtained inthe foregoing manner has a hydroxyl group, the acid dianhydride added asthe dehydrating agent may react with the hydroxyl group, so that it ispreferable that an amount of the acid anhydride is minimumstoichiometrically required in the imidization.

(3) Heat Treatment Under Reduced Pressure

An example of a process other than the thermal process and the chemicalprocess is imidization based on heat treatment under reduced pressure(for ease of description, this treatment is referred to asreduced-pressure heating process). By carrying out the reduced-pressureheating process, it is possible to obtain the soluble polyimide resin(E-1). Conditions of the reduced-pressure heating process are notparticularly limited as long as it is possible to carry out theimidization under the conditions. However, among the conditions, it ispreferable to define a heating condition and a pressure condition asfollows.

First, as to the heating condition, the temperature ranges from 80° C.to 400° C. However, in order to efficiently carry out the imidizationand dehydration, a lower limit thereof is preferably 100° C. or higher,more preferably 120° C. or higher. While, it is preferable that amaximum temperature (upper limit) in the heat treatment is a thermaldecomposition temperature or lower of the obtained soluble polyimideresin (E-1). Thus, the upper limit in the heating generally ranges fromapproximately 250° C. to 350° C. (temperature at which the imidizationis completed), preferably from approximately 180° C. to 350° C.

Next, the pressure condition is not particularly limited as long as thepressure is low. Specifically, the pressure preferably ranges from 0.001to 0.9 atomometer, more preferably from 0.001 to 0.8 atomometer, stillmore preferably from 0.001 to 0.7 atomometer. In other words, an upperlimit of the pressure in the reduced-pressure heating process is lessthan 1 atomometer, preferably 0.9 atomometer or less, more preferably0.8 atomometer or less, still more preferably 0.7 atomometer or less.While, a lower limit of the pressure is not particularly limited as longas the lower limit is 0.001 atomometer or more.

In the method for imidizing the polyamide acid in accordance with thereduced-pressure heating process, it is possible to positively excludewater generated by the imidization to the outside of the system. Thus,it is possible to suppress hydrolysis of the polyamide acid. Further,the acid dianhydride serving as a material for the polyamide acidcontains a one-side ring-opened substance or a double-side ring-openedsubstance as an impurity, but it is possible to carry out ring closurewith respect to the one-side ring-opened substance or the double-sidering-opened substance by adopting the reduced-pressure heating process.As a result, it is possible to raise a molecular weight of the obtainedsoluble polyimide resin (E-1).

Here, the following describes a specific method for directly imidizingthe polyamide acid solution by heating/drying the polyamide acidsolution under reduced pressure.

As described above, any method may be adopted as the method forimidizing the polyamide acid solution as long as it is possible toheat/dry the polyamide acid solution under reduced pressure. However,examples of the method are: a method in which the polyamide acidsolution is heated/dried by using a vacuum oven as a batch-type process;and a method in which the polyamide acid solution is heated/dried byusing a double-axis or triple-axis extruder having a decompressor as asequential-type process. By adopting either of the methods, it ispossible to carry out the imidization. Each of these methods may beselected in consideration for an amount of production and the like.

The double-axis or triple-axis extruder having a decompressor isobtained by providing a general melting extruder, heating/melting athermoplastic resin, with a device for removing the solvent throughdecompression. When the double-axis or triple-axis extruder is used, thepolyamide acid is kneaded by the extruder, and the solvent and watergenerated at the time of imidization are removed, thereby obtaining thesoluble polyimide resin (E-1).

In this manner, it is possible to obtain the soluble polyimide resin(E-1) of the present invention whose carboxylic acid equivalent rangesfrom 300 to 3000 or the soluble polyimide resin (E-1) of the presentinvention whose hydroxyl group equivalent ranges from 250 to 3000.Further, a carboxyl group or a hydroxyl group is included, so that it ispossible to provide the soluble polyimide resin which is soluble in analkaline aqueous solution.

Further, the polyamide acid solution is poured directly into a vesselhaving been subjected to a mold releasing treatment such as coating orthe like with a fluorine resin, and the polyamide acid solution isheated/dried under reduced pressure, so that it is also possible tocarry out dehydration ring closure with respect to the polyamide acidsolution.

(4) Solidification Process which Causes the Solvent not to Evaporate

In the thermal process and the chemical process or the reduced-pressureheating process, the solvent is evaporated during a process for carryingout the imidization. However, in the thermal process and the chemicalprocess, there is a method for obtaining the solid soluble polyimideresin (E-1) without evaporating the solvent for example. Specifically,in this method, a solution of the soluble polyimide resin (E-1) obtainedin the thermal process or the chemical process is added to a poorsolvent, and the polyimide resin is deposited, and the depositedpolyimide resin is dried, thereby obtaining the solid soluble polyimideresin (E-1).

A solvent used as the poor solvent used in this method is notparticularly limited as long as the poor solvent is favorably mixed withthe solution of the obtained soluble polyimide resin (E-1) but lessdissolves the soluble polyimide resin (E-1). Specific examples of thepoor solvent include acetone, methanol, ethanol, isopropanol, benzene,methylcellosolve (registered trademark), methyl ethyl ketone, water, andthe like.

According to the method, the soluble polyimide resin (E-1) is depositedin the poor solvent, so that it is possible not only to obtain the solidsoluble polyimide resin (E-1) but also to purify the soluble polyimideresin (E-1) by removing impurities. Examples of the impurities areunreacted monomer components (acid dianhydride and diamine), aceticanhydride and pyridine (in case of the chemical process), toluene andxylene (in case of the thermal process). In the method for carrying outthe deposition with the poor solvent, it is possible to purify and drythe soluble polyimide resin (E-1) by removing the impurities. Thus, itis possible to improve the quality of the obtained soluble polyimideresin (E-1).

<Second Method>

The second method for synthesizing (producing) the soluble polyimideresin (E-1) is a method in which the acid dianhydride containing atleast one kind of acid dianhydride is reacted with the isocyanatecomponent containing at least one kind of diisocyanate in the organicsolvent. At this time, as in the synthesis of the polyamide acid of thefirst method, the acid dianhydride component and the isocyanatecomponent are blended with each other so that they are substantiallyidentical with each other in a molar ratio.

In the second method, the method for reacting the monomer componentswith each other is not particularly limited. However, it is general toadopt a method in which: as in the synthesis of the polyamide acid, theacid dianhydride component and the isocyanate component which aresubstantially identical with each other in a molar ratio are dissolvedin the organic solvent, and then the resultant is stirred whilecontrolling reaction conditions until the polymerization is completed.The method allows preparation of a solution (soluble polyimide solution)by dissolving the polyimide acid in the organic solvent with a singlestep.

It is possible to react the monomer components without any solvent.However, it is preferable to use a catalyst in reaction between theisocyanate component and an active hydrogen compound. Examples of thecatalyst include: tertiary amines; an alkaline metal compound; analkaline earth metal compound; or metals such as cobalt, titanium, tin,zinc; and a semimetal compound; and the like. Note that, in the secondmethod, an order in which the acid dianhydride component and theisocyanate component are added is not particularly limited as long asthe addition is carried out in the same manner as in the synthesismethod of the polyamide acid.

In the second method, a synthesis condition of the soluble polyimideresin (E-1) is not particularly limited as long as it is possible tosufficiently synthesize polyimide by polymerizing the monomercomponents. In the present invention, among synthesis conditions, it ispreferable to define a temperature condition and the organic solvent touse as follows.

First, in the second method, the temperature condition under whichsynthesis reaction of the polyamide acid is carried out is notparticularly limited as long as the temperature range allowspolymerization of the acid dianhydride component and the isocyanatecomponent. However, generally, the reaction temperature preferablyranges from 50° C. to 220° C. Note that, the reaction time is notparticularly limited.

Next, the organic solvent used in the synthesis reaction of the secondmethod is not particularly limited as long as the solvent cansufficiently dissolve the obtained soluble polyimide resin (E-1).However, as in the case of synthesizing the polyamide acid, it ispreferable to select an organic solvent which can favorably dissolve thepolyimide and whose boiling point is as low as possible, in order tomake it easier to stir the solvent while suppressing increase ofviscosity in synthesizing the polyimide, to make it easier to dry theobtained soluble polyimide resin (E-1), and to realize a similar object.Thus, it is possible to make the production steps of the solublepolyimide resin (E-1) more efficient.

Specific examples of the organic solvent which can be used in thesynthesis reaction of the second method include: amides organic solventsuch as N,N-dimethyl formamide, N,N-dimethyl acetamide, N,N-diethylacetamide, N,N-dimethylmethoxy acetamide, N-methyl-2-pyrrolidone, andhexamethyl phosphamido; lactams organic solvent such as N-methylcaprolactam; urea organic solvent such as 1,3-dimethyl-2-imidazolidinonand tetramethyl area; hydrocarbons organic solvent such as1,2-dimethoxyethane, 1,2-bis(2-methoxyethyl)ethane, andbis[2-(2-methoxyethoxy)ethane]; ethers organic solvent such asbis(2-methoxyethyl)ether, bis[2-(2-methoxy)ethyl]ether, 1,3-dioxane,1,4-dioxane, tetrahydrofuran, and digrime; esters organic solvent suchas γ-butyrolactone; pyridines organic solvent such as pyridine andpicoline; sulfurs organic solvent such as dimethyl sulfoxide, dimethylsulfone, and sulforan; nitro organic solvent such as nitromethane,nitroethane, and nitrobenzene; nitryls organic solvent such asacetonitrile; and the like. However, the organic solvent is not limitedto them. The organic solvents may be independently used, or a suitablecombination of two or more kinds may be used.

<Soluble Polyimide Solution>

In preparing the photosensitive resin composition of the presentinvention, the obtained soluble polyimide resin (E-1) is dissolved inthe desired organic solvent, thereby using the resultant as the solublepolyimide solution. The organic solvent used in the soluble polyimidesolution is not particularly limited as long as the organic solvent candissolve the obtained soluble polyimide resin (E-1). However, an examplethereof is an organic polar solvent used in the synthesis reaction ofthe polyamide acid. These organic solvents may be independently used, ora suitable combination of two or more kinds may be used.

A concentration of the soluble polyimide solution is not particularlylimited, and the concentration may be suitably determined depending onuse (purpose of use) of the obtained photosensitive resin compositionand how the photosensitive resin composition is used. However, theconcentration generally ranges from 1 to 30 wt %. Further, the viscosityof the soluble polyimide solution is not particularly limited. However,generally, in case where N-methyl-2-pyrrolidone solution is used as thesoluble polyimide solution, it is preferable that the logarithmicviscosity at 30° C. ranges from 0.1 to 2.5 (deciliter/gram). When thelogarithmic viscosity is within this range, this allows a molecularweight of the soluble polyimide resin (E-1) have a generally favorablevalue.

Note that, in the photosensitive resin composition according to thepresent invention, at least one kind of the soluble polyimide resin(E-1) is included, two or more kinds of soluble polyimide resins (E-1)may be included, or a polyimide resin other than these resins may beincluded. Further, a polyamide acid serving as a precursor that has notbeen imidized may be used as the soluble polyimide resin (E-1). Inpreparing the heat resistance resin composition and the photosensitiveresin composition, it is preferable to use not the polyamide acid butthe imidized soluble polyimide resin (E-1) since the imidized solublepolyimide resin (E-1) hardly causes reaction in blending the componentsand its stability is high.

In the photosensitive resin composition according to the presentinvention, an amount of the soluble polyimide resin (E-1) blended is notparticularly limited. However, when a total amount of the photosensitiveresin composition is 100 wt (mass) %, its lower limit is preferably 20wt % or more, more preferably 30 wt % or more. While, its upper limit ispreferably 80 mass% or less, more preferably 60 mass% or less. When theamount of the soluble polyimide resin (E-1) blended is within thisrange, it is possible to enhance the easiness to process thephotosensitive resin composition and it is possible to improveproperties (dielectric property, heat resistance, and the like) of acured resin (cured product) obtained by curing the photosensitive resincomposition.

<Epoxy Denaturalized Polyimide Resin>

As described above, it is preferable that the soluble polyimide resin(E-1) used in the present invention has a hydroxyl group or a carboxylgroup. An epoxy compound having an epoxy group (for ease of description,the epoxy compound added to the soluble polyimide resin is referred toas a PI epoxy compound) is added to the soluble polyimide resin having acarboxyl group, so that the carboxyl group of the soluble polyimideresin and the epoxy group of the epoxy compound are reacted with eachother. As a result, an ester bond and a secondary hydroxyl group aregenerated as CO—O—CH₂—CH(OH)—. The compound having the ester bond andthe secondary hydroxyl group less takes in metal ions at the time ofdevelopment, so that its electric property does not drop. This fact wasfound by the inventors of the present invention. In addition, it wasfound that development can be carried out with an alkaline aqueoussolution. Thus, it is preferable that: in the soluble polyimide resin(E-1) of the present invention, the carboxyl group and the epoxy groupof the soluble polyimide resin are reacted with each other so as toproduce a soluble polyimide resin having been epoxy-denaturalized(hereinafter, referred to as epoxy denaturalized polyimide resin).

That is, it is preferable to produce the epoxy denaturalized polyimideresin by denaturalizing the soluble polyimide resin (E-1) whosecarboxylic acid equivalent ranges from 300 to 3000 with a PI epoxycompound having an epoxy group. The carboxylic acid equivalent of thesoluble polyimide resin (E-1) constituting the epoxy denaturalizedpolyimide resin preferably ranges from 350 to 2500, more preferably from350 to 2000. It is not preferable that the carboxylic acid equivalentexceeds 3000 since the epoxy denaturalized polyimide resin is lessdissolved in an aqueous alkaline developer and developing time islonger. Further, when diamine having two or more carboxyl groups isused, it is possible to realize the carboxylic acid equivalent of 300 orless, but it is necessary to use a monomer having a large molecularweight to some extent so as to raise the solubility, so that it isdifficult to set the carboxylic acid equivalent to 300 or less.

In order to realize the aforementioned carboxylic acid equivalent, it ispreferable to use diamine having two or more carboxyl groups in itsmolecule. It is preferable to use the diamine since it is possible tocopolymerize diamines different from each other in realizing apredetermined carboxylic acid equivalent, so that it becomes easier todesign properties.

Note that, a hydroxyl group equivalent of the epoxy denaturalizedpolyimide resin preferably ranges from 250 to 3000, more preferably from300 to 2000, most preferably from 300 to 1500. It is not preferable thatthe hydroxyl group equivalent exceeds 3000 since the epoxy denaturalizedpolyimide resin is less dissolved in the alkaline aqueous solution andit is difficult to carry out the development. Further, it is notpreferable that the hydroxyl group equivalent is less than 250 since theheat resistance drops and its large amount of water absorptive hydroxylgroups causes the resultant to absorb more moisture.

Next, a production method of the epoxy denaturalized polyimide resin isdescribed as follows. The soluble polyimide resin (E-1) having acarboxyl group is dissolved in an organic solvent, and the PI epoxycompound and the carboxyl group of the soluble polyimide resin (E-1) arereacted with each other, thereby obtaining the epoxy denaturalizedpolyimide resin.

The organic solvent used in the reaction is not particularly limited aslong as the organic solvent does not react with the epoxy group and candissolve the soluble polyimide resin (E-1) having a carboxyl group.Specific examples of the organic solvent include: sulfoxide solvent suchas dimethyl sulfoxide and diethyl sulfoxide; formamide solvent such asN,N-dimethyl formamide and N,N-diethyl formamide; acetamide solvent suchas N,N-dimethyl acetamide and N,N-diethyl acetamide; pyrrolidone solventsuch as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone; ether solventsuch as tetrahydrofuran and dioxane; alcohol solvent such as methanol,ethanol, and butanol; cellosolve such as butyl cellosolve; hexamethylphosphoamide; γ-butyrolactone; and the like. Additional examples thereofare aromatic hydrocarbons such as xylene and toluene. These organicsolvents may be independently used, or a suitable combination of two ormore kinds may be used. It is general that the epoxy denaturalizedpolyimide resin used in the present invention is finally used afterremoving the solvent therefrom, so that it is important to select asolvent whose boiling point is as low as possible.

<PI Epoxy Compound>

Here, the PI epoxy compound reacted with the soluble polyimide resin(E-1) having a carboxyl group is described as follows. Preferableexamples of the PI epoxy compound include an epoxy compound having twoor more epoxy groups and an epoxy compound having an epoxy group and anunsaturated double bond or an unsaturated triple bond.

The epoxy compound having two or more epoxy groups is a compound whichhas two or more epoxy groups in its molecule. Specific examples thereofinclude: bisphenol resins such as Epikote 828 (commercial name: productof Shell Chemicals Japan Ltd.); o-cresolnovolak-type epoxy resins suchas 180S65 (commercial name: product of Shell Chemicals Japan Ltd.);bisphenol A novolak resins such as 157S70 (commercial name: product ofShell Chemicals Japan Ltd.); trishydroxyphenylmethanenovolak resins suchas 1032H60 (commercial name: product of Shell Chemicals Japan Ltd.);naphthalenearalkylnovolak resins such as ESN375 (commercial name:product of Nippon Steel Chemical Group); tetraphenylolethane 1031 S(commercial name: product of Shell Chemicals Japan Ltd.); glycidyl aminetype resins such as YGD414S (commercial name: product of Tohto KaseiCO., Ltd.), trishydroxyphenylmethane EPPN502H (commercial name: NipponKasei Chemical Co., Ltd.), special bisphenol VG3101L (commercial name:product of Mitsui Chemicals. Inc.), special naphthol NC7000 (commercialname: product of Nippon Kayaku Co., Ltd.), TETRAD-X and TETRAD-C (bothof which are commercial names: products of MITSUBISHI GAS CHEMICALCOMPANY. INC.; and the like. However, the epoxy compound having two ormore epoxy groups is not limited to them. These PI epoxy compounds maybe independently used, or a suitable combination of two or more kindsmay be used.

Further, the epoxy compound having an epoxy group and an unsaturateddouble bond is a compound which has an epoxy compound and an unsaturateddouble bond in its molecule. Specific examples thereof includes allylglycidyl ether, glycidyl acrylate, glycidyl methacrylate, glycidyl vinylether, and at least one kind of a epoxy compound selected from compoundseach of which has a structure represented by the following formula (15).However, the PI epoxy compound is not limited to them.

where R¹⁴ represents a hydrogen or methyl group. These PI epoxycompounds may be independently used, or a suitable combination of two ormore kinds may be used.

Further, the epoxy compound having an epoxy group and an unsaturatedtriple bond is a compound which has an epoxy group and an unsaturatedtriple bond in its molecule. Specific examples thereof include propargylglycidyl ether, glycidyl propioate, ethynyl glycidyl ether, and thelike, but the PI epoxy compound is not limited to them. These PI epoxycompounds may be independently used, or a suitable combination of two ormore kinds may be used.

In order to react the PI epoxy compound with the soluble polyimide resin(E-1) having a carboxyl group, they are dissolved in the organicsolvent, and the mixture is heated. It is possible to adopt any methodfor dissolving these components in the organic solvent, and the reactiontemperature is preferably 40° C. or higher and 130° C. or lower.Particularly, in case of using the PI epoxy compound having anunsaturated double bond or an unsaturated triple bond, it is preferableto carry out the reaction at such temperature that the unsaturateddouble bond or the unsaturated triple bond is decomposed or cross-linkedby heat. Specifically, it is preferable to carry out the reaction at 40°C. or higher and 100° C. or lower, and it is more preferable to carryout the reaction at 50° C. or higher and 90° C. or lower. Further, thereaction time preferably ranges from several minutes to about 8 hours.In this manner, it is possible to obtain a solution of the epoxydenaturalized polyimide resin.

Note that, a thermoplastic resin such as polyester, polyamide,polyurethane, polycarbonate, and the like may be mixed with the epoxydenaturalized polyimide resin solution, or a thermosetting resin such asepoxy resin, acryl resin, bismaleimide, bisallylnadiimide, a phenolicresin, a cyanate resin, and the like may be mixed with the epoxydenaturalized polyimide resin solution. Further, various kinds ofcoupling agents may be mixed.

When a curing agent generally used for an epoxy resin is blended withthe epoxy denaturalized polyimide resin used in the present invention,it may be possible to obtain a cured product having favorableproperties. This condition is confirmed particularly in an epoxydenaturalized polyimide resin obtained by reacting the PI epoxy compoundhaving two or more epoxy groups with the soluble polyimide resin (E-1)having a carboxyl group. Typical examples of the epoxy resin curingagent used in this case include amine curing agents, imidazole curingagents, acid dianhydride curing agents, acid curing agents, and thelike, but the curing agent is not particularly limited.

[Other Component (F)]

The photosensitive resin composition according to the present inventionmay include not only the double bond phosphazene compound and thesoluble polyimide resin (E-1) but also other component (F). The “othercomponent (F)” is suitably selected depending on usage thereof, and isnot particularly limited. However, specific examples thereof include aphotoreaction initiator (F-1), a sensitizer (F-2), a photopolymerizationassistant (F-3), a compound having a carbon-carbon double bond (F-4), acomposition epoxy resin (F-5), an inorganic filler, and the like.

<Photoreaction Initiator (F-1)>

It is more preferable that the photosensitive resin compositionaccording to the present invention contains the photoreaction initiator(F-1) in order to have the photosensitivity. An example of the compoundused as the photoreaction initiator (F-1) is an acylphosphine oxidecompound which generates a radical by light whose wavelength is long asa g line and is represented by the following formula. (16) or anacylphosphine oxide compound represented by the following formula (17).

where each of R¹⁵, R¹⁶, and R¹⁷ represents C₆H₅—, C₆H₄(CH₃)—,C₆H₂(CH₃)₃—, (CH₃)₃C—, C₆H₃Cl₂—, C₆H₃(CH₃)₂—, C₅H₄Cl—, or C₆H₂Cl₃—.

where each of R¹⁸, R¹⁹, and R²⁰ represents C₆H₅—, a methoxy group, anethoxy group, C₆H₄(CH₃)—, C₆H₂(CH₃)₃—, C₆H₃(CH₃)₂—, C₆H₄Cl—, orC₆H₂Cl₃—. A radical generated from each of the compounds reacts with areaction group (a vinyl group, an acryloyl group, a methacryloyl group,an acryl group, and the like) having an unsaturated double bond, andpromotes cross-linking.

It is preferable to use the acylphosphineoxide compound represented bythe formula (16) as the photoreaction initiator (F-1) since thisgenerates two radicals. It is more preferable to use the acylphosphineoxide compound represented by the formula (17) since this generates fourradicals through a cleavage.

As a radical initiator, various kinds of peroxides can be combined withthe following sensitizer (F-2). Among them, it is particularlypreferable to combine 3,3′,4,4′-tetra (t-butylperoxycarbonyl)benzophenonwith the sensitizer (F-2).

<Sensitizer (F-2)>

In order to achieve practical photosensitivity, the photosensitive resincomposition according to the present invention may include thesensitizer (F-2). Preferable specific examples of the sensitizer (F-2)include Michler's ketone, bis-4,4′-diethylaminobenzophenon, benzophenon,camphor quinone, benzyl, 4,4′-dimethylaminobenzyl, 3,5-bis(diethylaminobenzylidene)-N-methyl-4-pipelidone, 3,5-bis(dimethylaminobenzylidene)-N-methyl-4-pipelidone, 3,5-bis(diethylaminobenzylidene)-N-ethyl-4-pipelidone,3,3′-carbonylbis(7-diethylamino)coumarin, riboflavintetrabutylate,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one,2,4-dimethylthioxanthene, 2,4-diethylthioxanthene,2,4-diisopropylthioxanthene, 3,5-dimethylthioxanthene,3,5-diisopropylthioxanthene,1-phenyl-2-(ethoxycarbonyl)oxyiminopropane-1-one, benzoin ether,benzoinisopropylether, benzanthrone, 5-nitroacenaphthene,2-nitrofluorene, anthrone, 1,2-benzanthraquinone,1-phenyl-5-mercapto-1H-tetrazole, thioxanthene-9-one, 10-thioxanthenone,3-acetylindole, 2,6-di(p-dimethylaminobenzal)-4-carboxycyclohexanone,2,6-di(p-dimethylaminobenzal)-4-hydroxycyclohexanone,2,6-di(p-diethylaminobenzal)-4-carboxycyclohexanone,2,6-di(p-diethylaminobenzal)-4-hydroxycyclohexanone,4,6-dimethyl-7-ethylaminocoumarin, 7-diethylamino-4-methylcoumarin,7-diethylamino-3-(1-methylbenzoimidazolyl)coumarin,3-(2-benzoimidazolyl)-7-diethylaminocoumarin,3-(2-benzothiazolyl)-7-diethylaminocoumarin,2-(p-dimethylaminostyryl)benzoxazole,2-(p-dimethylaminostilyl)quinoline, 4-(p-dimethylaminostilyl)quinoline,2-(p-dimethylaminostilyl)benzothiazole,2-(p-dimethylaminostilyl)-3,3-dimethyl-3H-indole, and the like, but thesensitizer is not limited to them.

With respect to 100 parts by weight of the phosphazene compound of thepresent invention, an amount of the sensitizer (F-2) blended preferablyranges from 0.1 to 50 parts by weight, more preferably from 0.3 to 20parts by weight. It is not preferable that the amount deviates from theforegoing range (0.1 to 50 parts by weight) because it is impossible toobtain the sensitization effect and this may have a bad influence on thedeveloping property. Note that, as the sensitizer (F-2), one kind of acompound may be used, or a mixture of plural kinds may be used.

<Photopolymerization assistant (F-3)>

In order to achieve practical photosensitivity, the photosensitive resincomposition according to the present invention may include aphotopolymerization assistant (F-3). Specific examples of thephotopolymerization assistant (F-3) include 4-diethylaminoethylbenzoate,4-dimethylaminoethylbenzoate, 4-diethylaminopropylbenzoate,4-dimethylaminopropylbenzoate, 4-dimethylaminoisoamylebenzoate,N-phenylglycine, N-methyl-N-phenylglycine, N-(4-cyanophenyl)glycine,4-dimethylaminobenzonitrile, ethyleneglycoldithioglycolate,ethyleneglycol di(3-mercaptopropionate),trimethylolpropanethioglycolate, trimethylolpropanetri(3-mercaptopropionate), pentaerythritoltetrathioglycolate,pentaerythritol tetra(3-mercaptopropionate),trimethylolethanetrithioglycolate, trimethylolpropanetrithioglycolate,trimethylolethane tri(3-mercaptopropionate),dipentaerythritolhexa(3-mercaptopropionate), thioglycolic acid,α-mercaptopropionic acid, t-butylperoxybenzoate,t-butylperoxymethoxybenzoate, t-butylperoxynitrobenzoate,t-butylperoxyethylbenzoate, phenylisopropylperoxybenzoate, dit-butyldiperoxyisophthalate, tri t-butyltriperoxytrimellitate, trit-butyltriperoxytrimesitate, tetra t-butyltetraperoxypyromellitate,2,5-dimethyl-2,5-di(benzoylperoxy)hexane,3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone,3,3,4,4′-tetra(t-amylperoxycarbonyl)benzophenone,3,3′,4,4′-tetra(t-hexylperoxycarbonyl)benzophenone,2,6-di(p-azidobenzal)-4-hydroxycyclohexanone,2,6-di(p-azidobenzal)-4-carboxycyclohexanone,2,6-di(p-azidobenzal)-4-methoxycyclohexanone,2,6-di(p-azidobenzal)-4-hydroxycyclohexanone,3,5-di(p-azidobenzal)-1-methyl-4-piperidone,3,5-di(p-azidobenzal)-4-piperidone,3,5-di(p-azidobenzal)-N-acetyl-4-piperidone,3,5-di(p-azidobenzal)-N-methoxycarbonyl-4-piperidone,2,6-di(p-azidobenzal)-4-hydroxycyclohexanone,2,6-di(m-azidobenzal)-4-carboxycyclohexanone,2,6-di(m-azidobenzal)-4-methoxycyclohexanone, 2,6-di(m-azidobenzal)-4-hydroxycyclohexanone, 3,5-di(m-azidobenzal)-N-methyl-4-piperidone,3,5-di(m-azidobenzal)-4-piperidone,3,5-di(m-azidobenzal)-N-acetyl-4-piperidone,3,5-di(m-azidobenzal)-N-methoxycarbonyl-4-piperidone,2,6-di(p-azidecinnamyliden)-4-hydroxycyclohexanone,2,6-di(p-azidecinnamyliden)-4-carboxycyclohexanone,2,6-di(p-azidecinnamyliden)-4-cyclohexanone,3,5-di(p-azidecinnamyliden)-N-methyl-4-piperidone, 4,4′-diazidochalcone,3,3′-diazidochalcone, 3,4′-diazidochalcone, 4,3′-diazidochalcone,1,3-diphenyl-1,2,3-propanetrione-2-(o-acetyl)oxime,1,3-diphenyl-1,2,3-propanetrione-2-(o-n-propylcarbonyl)oxime,1,3-diphenyl-1,2,3-propanetrione-2-(o-methoxycarbonyl)oxime,1,3-diphenyl-1,2,3-propanetrione-2-(o-ethoxycarbonyl)oxime,1,3-diphenyl-1,2,3-propanetrione-2-(o-benzoyl)oxime,1,3-diphenyl-1,2,3-propanetrione-2-(o-phenyloxycarbonyl)oxime,1,3-bis(p-methylphenyl)-1,2,3-propanetrione-2-(o-benzoyl)oxime,1,3-bis(p-methoxyphenyl)-1,2,3-propanetrione-2-(o-ethoxycarbonyl)oxime,1-(p-methoxyphenyl)-3-(p-nitrophenyl)-1,2,3-propanetrione-2-(o-phenyloxycarbonyl)oxime,and the like, but the photopolymerization assistant is not limited tothem. Further, as another assistant, it is possible to usetrialkylamines such as triethylamine, tributylamine, triethernolamine,and the like.

With respect to 100 parts by weight of the phosphazene compound of thepresent invention, an amount of the photopolymerization assistantblended preferably ranges from 0.1 to 50 parts by weight, morepreferably from 0.3 to 20 parts by weight. It is not preferable that theamount deviates from the foregoing range (0.1 to 50 parts by weight)because it is impossible to obtain the desired sensitization effect andthis may have a bad influence on the developing property. Note that, asthe photopolymerization assistant (F-3), one kind of a compound may beused, or a mixture of plural kinds may be used.

<Compound having a Carbon-carbon Double Bond (Copolymerizable Polymer)(F-4)>

Further, in order to achieve practical photosensitivity, thephotosensitive resin composition according to the present invention mayinclude not only the sensitizer and the photopolymerization assistantbut also a compound having a carbon-carbon double bond (copolymerizablepolymer) (F-4) (for ease of description, this compound is referred to asa copolymerizable monomer). The copolymerizable monomer (F-4) has acarbon-carbon double bond (unsaturated double bond) in its molecule, sothat this facilitates the photopolymerization.

Specific examples of the copolymerizable monomer (F-4) include bisphenolF EO denaturalized (n=2 to 50) diacrylate, bisphenol A EO denaturalized(n=2 to 50) diacrylate, bisphenol S EO denaturalized (n=2 to 50)diacrylate, 1,6-hexandiol diacrylate, neopentylglycol diacrylate,ethyleneglycol diacrylate, pentaerythritol diacrylate,trimethylolpropane triacrylate, pentaerythritol triacrylate,dipentaerythritol hexa acrylate, tetramethylol propane tetra acrylate,tetraethyleneglycol diacrylate, 1,6-hexanediol dimethacrylate,neopentylglycol dimethacrylate, ethyleneglycol dimethacrylate,pentaerythritol dimethacrylate, trimethylol propane trimethacrylate,pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate,tetramethylol propane tetramethacrylate, tetraethyleneglycoldimethacrylate, methoxydiethyleneglycol methacrylate,methoxypolyethyleneglycol methacrylate, β-metachroyl oxyethyl hydrogenphthalate, β-metachroyl oxyethyl hydrogen succinate,3-chloro-2-hydroxypropyl methacrylate, steallyl methacrylate,phenoxyethyl acrylate, phenoxydiethyleneglycol acrylate,phenoxypolyethyleneglycol acrylate, β-acryloyloxtethyl hydrogensuccinate, lauryl acrylate, ethyleneglycol dimethacrylate,diethyleneglycol dimethacrylate, triethyleneglycol dimethacrylate,polyethyleneglycol dimethacrylate, 1,3-buthyleneglycol dimethacrylate,1,6-hexanediol dimethacrylate, neopentylglycol dimethacrylate,polypropyleneglycol dimethacrylate, 2-hydroxy-1,3dimethachroxypropane,2,2-bis [4-(methachroxyethoxy)phenyl] propane, 2,2-bis [4-(methachroxydiethoxy)phenyl] propane, 2,2-bis [[4-(methachroxy polyethoxy)phenyl]propane, polyethyleneglycol dichrylate, tripropyleneglycol diacrylate,polypropyleneglycol diacrylate, 2,2-bis [4-(acryloxy diethoxy)phenyl]propane, 2,2-bis [4-(acryloxy polyethoxy)phenyl] propane,2-hydroxy-1-acryloxy3-methachloxy propane, trimethylol propanetrimethacrylate, tetramethylol methane triacrylate, tetramethyrolmethane tetraacrylate, methoxy dipropyleneglycol methacrylate,methoxytriethyleneglycol acrylate, nonylphenoxypolyethyleneglycolacrylate, nonylphenoxypolypropyleneglycol acrylate,1-acryloyloxypropyl-2-phthalate, isosteallyl acrylate,polyoxyethylenealkylether acrylate, nonylphenoxyethyleneglycol acrylate,polypropyleneglycol dimethacrylate, 1,4-butanediol dimethacrylate,3-methyl-1,5-pentanediol dimethacrylate, 1,6-mexanediol dimethacrylate,1,9-nonanediol methacrylate, 2,4-diethyl-1,5-pentanediol dimethacrylate,1,4-cyclohexanedimethanol dimethacrylate, dipropyleneglycol diacrylate,tricyclodecanedimethanol diacrylate, 2,2-hydrogenerated bis [4-(acryloxypolyethoxy)phenyl] propane, 2,2′-bis [4-(acryloxy polypropoxy)phenyl]propane, 2,2-bis [4-(acryloxy polyethoxy)phenyl] propane,2,4-diethyl-1,5-pentanediol diacrylate, ethoxylated tothymethylolpropanetriacrylate, propoxylated tothymethylolpropane triacrylate, isocyanuricacid tri(ethaneacrylate), pentathritol tetra acrylate, ethoxylatedpentathritol tetra acrylate, propoxylated pentathritol tetra acrylate,ditrimethylolpropane tetra acrylate, dipentaerythritol polyacrylate,isocyanuric acid triallyl, glycidyl methacrylate, glycidyl allylether,1,3,5-triacryloylhexahydro-s-triazine, triallyl1,3,5-benzenecarboxylate,triallyl amine, triallyl citrate, triallyl phosphate, allobarbital,diallyl amine, diallyl dimethyl silane, diallyl disulfide, diallylether, diallyl cyanulate, diallyl isophthalate, diallyl telephtalate,1,3-diallyloxy-2-propanol, diallyl sulfide diallyl maleate,4,4′-isopropyliden diphenol dimethacrylate, 4,4′-isopropyliden diphenoldiacrylate, and the like, but the copolymerizable monomer (F-4) is notlimited to them.In order to improve the cross-linked density, it isparticularly preferable to use a bifunctional or further multifunctionalmonomer. Note that, the EO denaturalization is an ethyleneoxidedenaturalized portion.

Further, in order to exhibit the flexibility of a cured resin (forexample, a photosensitive dry film resist) obtained by curing thephotosensitive resin composition according to the present invention, itis preferable to use, as a copolymerizable monomer, bisphenol F EOdenaturalized diacrylate, bisphenol A EO denaturalized diacrylate,bisphenol S EO denaturalized diacrylate, bisphenol F EO denaturalizeddimathacrylate, bisphenol A EO denaturalized dimethacrylate, andbisphenol S EO denaturalized dimethacrylate. Particularly, the number ofrecurring units of denaturalized EO contained in a single molecule ofdiacrylate or methacrylate preferably ranges from 2 to 50, morepreferably from 2 to 40. When the number of recurring units of EO iswithin the foregoing preferable range, the obtained photosensitive resincomposition has higher solubility with respect to the alkaline aqueoussolution, so that the developing time is reduced. Note that, it is notpreferable that the number of recurring units of EO is 50 or more,because the heat resistance is likely to drop under this condition.

With respect to 100 parts by weight of the phosphazene compound of thepresent invention, an amount of the copolymerizable monomer (F-1)blended preferably ranges from 1 to 200 parts by weight, more preferablyfrom 3 to 150 parts by weight. It is not preferable that the amount ofthe copolymerizable monomer blended deviates from the range (1 to 200parts by weight) because it is impossible to obtain the desiredsensitization effect and this may have a bad influence on the developingproperty. Note that, as the copolymerizable monomer (F-4), one kind of acompound may be used, or a mixture of plural kinds may be used.

<Composition Epoxy Resin (F-5)>

Further, in order to improve the bonding property, the photosensitiveresin composition according to the present invention may include anepoxy resin (for ease of description, the epoxy resin included in thephotosensitive resin composition is referred to as a composition epoxyresin). The composition epoxy resin (F-5) is not particularly limited aslong as the compound has an epoxy group in its molecule. However,specific examples thereof include: bisphenol resins such as Epikote 828(commercial name: product of Shell Chemicals Japan Ltd.);o-cresolnovolak-type epoxy resins such as 180S65 (commercial name:product of Shell Chemicals Japan Ltd.); bisphenol A novolak resins suchas 157S70 (commercial name: product of Shell Chemicals Japan Ltd.);trishydroxyphenylmethanenovolak resins such as 1032H60 (commercial name:product of Shell Chemicals Japan Ltd.); naphthalenearalkylnovolak resinssuch as ESN375 (commercial name: product of Nippon Steel ChemicalGroup); tetraphenylolethane 1031S (commercial name: product of ShellChemicals Japan Ltd.); glycidyl amine type resins such as YGD414S(commercial name: product of Tohto Kasei CO., Ltd.),trishydroxyphenylmethane EPPN502H (commercial name: Nippon KaseiChemical Co., Ltd.), special bisphenol VG3101L (commercial name: productof Mitsui Chemicals. Inc.), special naphthol NC7000 (commercial name:product of Nippon Kayaku Co., Ltd.), TETRAD-X and TETRAD-C (both ofwhich are commercial names: products of MITSUBISHI GAS CHEMICAL COMPANY.INC.; and the like.

Further, as the composition epoxy resin (F-5), it is possible to mix anepoxy resin having an epoxy group and an unsaturated double bond or anunsaturated triple bond in its molecule. Examples of the epoxy resininclude allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate,glycidyl vinyl ether, propargyl glycidyl ether, glycidyl propioate,ethynyl glycidyl ether, and the like.

Further, the composition epoxy resin can be used as a thermosettingresin. In this manner, in case where the composition epoxy resin ismixed with the photosensitive resin composition, the composition epoxyresin not only improves the bonding property but also serves as thethermosetting agent. It is preferable to mix the composition epoxy resinwith the photosensitive resin composition as the thermosetting resinsince it is possible to obtain a thermosetting resin which is made ofphotosensitive resin composition and has favorable properties. Anycuring agent may be used as the thermosetting resin used here as long asthe curing agent is made of epoxy resin: any thermosetting resin such asamines, imidazoles, acid dianhydrides, acids, and similar thermosettingresin may be used. Further, various kinds of coupling agents may bemixed therewith.

<Inorganic Filler or the Like (F-6)>

The photosensitive resin composition according to the present inventionmay further include an inorganic filler such as talc, mica, silica,alumina, barium sulfate, and magnesium oxide, or may further include acolor pigment such as cyanine green and cyanine blue. Further, it ispossible to use a thixotropy agent, an antifoaming agent, a levellingagent, an ultraviolet ray absorbing agent, an oxidation inhibitor, and apolymerization inhibitor.

Further, in the photosensitive resin composition, a thermosetting resinother than the composition epoxy resin may be mixed. Also in this case,it is possible to obtain a photosensitive resin composition havingfavorable properties, so that it is preferable to mix the thermosettingresin other than the composition epoxy resin. Examples of thethermosetting resin used here include bismaleimide, bisallylnadiimide, aphenolic resin, a cyanate resin, and the like.

[Photosensitive Resin Composition having no Soluble Polyimide Resin (D)]

As the photosensitive resin composition according to the presentinvention, it is possible to use not only the photosensitive resincomposition containing at least the phosphazene compound and the solublepolyimide resin (D) but also a photosensitive resin compositioncontaining at least the phosphazene compound and the photoreactioninitiator (F-1). In this case, not only the phosphazene compound and thephotoreaction initiator (F-1) but also a resin other than the solublepolyimide resin (D) may be contained.

As the resin other than the soluble polyimide resin (D), it ispreferable to use a resin having properties equal with or superior toproperties of the photosensitive resin composition containing thesoluble polyimide resin (D) in terms of flame retardancy and easiness toprocess the obtained photosensitive resin composition. Examples thereofinclude a resin having a carboxyl group (for ease of description, thisresin is referred to as a carboxyl-group resin) and a resin having ahydroxyl group (for ease of description, this resin is referred to as ahydroxyl-group resin). A weight-average molecular weight of thecarboxyl-group resin or the hydroxyl-group resin preferably ranges from10000 to 300000, more preferably from 10000 to 150000, still morepreferably from 20000 to 100000. In case where the weight-averagemolecular weight is less than 10000, when the photosensitive resincomposition is used as a photosensitive resin film, the photosensitivefilm is likely to be brittle. Adversely, when the weight-averagemolecular weight exceeds 300000, it is hard to develop thephotosensitive resin composition, so that the resolution is likely todrop.

Examples of the carboxyl-group resin and the hydroxyl-group resin are asfollows, but the carboxyl-group resin and the hydroxyl-group resin arenot limited to these examples. An example of the carboxyl-group resin isacrylic copolymers obtained by copolymerizing acrylic compounds, servingas a main component, with an ethylene unsaturated carboxylic acid.Further, it is possible to use acrylic copolymers obtained bycopolymerizing the acrylic compounds with other monomer, which iscopolymerizable with (meth)acrylic compounds, as well as the ethyleneunsaturated carboxylic acid.

Examples of the (meth)acrylic compounds include methyl(meth)acrylate,ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate,hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate,cyclohexyl(meth)acrylate, benzyl(meth)acrylate,dimethylaminoethyl(meth)acrylate, hydroxyethyl(meth)acrylate,hydroxypropyl(meth)acrylate, glycidyl(meth)acrylate. These (meth)acryliccompounds may be independently used, or a suitable combination of two ormore kinds may be used.

Examples of the ethylene unsaturated carboxylic acid include:monocarboxylic acid such as acrylic acid, methacrylic acid, and crotonicacid; dicarboxylic acid such as maleic acid and fumaric acid; or ananhydride or a half ester etc. thereof. These ethylene unsaturatedcarboxylic acids may be independently used, or a suitable combination oftwo or more kinds may be used.

Examples of other monomer include: acrylamide compounds such as(meth)acrylamide, 2,2,3,3-tetrafluoropropyl(meth)acrylamide, anddiacetoneacrylamide; compound having a vinyl group, e.g., vinylacetate,alkylvinylether, and (meth)acrylnitryl; styrene; α-methylstyrene;tetrahydrofurfuryl(meth)acrylate; diethylaminoethyl(meth)acrylate;2,2,2-trifluoroethyl(meth)acrylate; and the like. These monomers may beindependently used, or a suitable combination of two or more kinds maybe used.

In case of obtaining acrylic copolymers having a carboxyl group bycopolymerizing the (meth)acrylic compounds with the ethylene unsaturatedcarboxylic acid and other monomer, a weight ratio of the (meth)acryliccompounds, the ethylene unsaturated carboxylic acid, and other monomeris not particularly limited, but an amount of the (meth)acrylic compoundcomponent contained preferably ranges from 15 to 85 wt %, morepreferably from 30 to 80 wt %. Further, an amount of the ethyleneunsaturated carboxylic acid component contained preferably ranges from15 to 85 wt %, more preferably from 20 to 70 wt %. An amount of othermonomer component contained preferably ranges from 0 to 70 wt %.

Examples of the hydroxyl-group resin include a phenolic resin, aresorcinol resin, and the like. Further, as other resin, not only thecarboxyl-group resin and the hydroxyl-group resin but also a polyesterresin, a polyamide resin, a polyimide resin, a polyurethane resin, anepoxy resin, and the like may be used. It is possible to use alsooligomer such as an epoxy acrylate resin and the like.

[Photosensitive Resin Composition Solution]

The photosensitive resin composition according to the present inventionmay include an appropriate organic solvent. When the photosensitiveresin composition is dissolved in the appropriate organic solvent, thephotosensitive resin composition can be used in a solution (varnish)state. This is convenient in applying and drying the photosensitiveresin composition. As the solvent used in this case, it is preferable touse an aprotic polar solvent in terms of the solubility. Specificpreferable examples thereof include N-methyl-2-pyrrolidone,N-acetyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N,N-dimethylformamide,N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphortriamide,N-acetyl-ε-caprolactam, dimethylimidazolidinon,diethylglycoldimethylether, triethyleneglycoldimethylether,γ-butyrolactone, dioxane, dioxolane, tetrahydrofuran, chloroform, andmethylene chloride. They may be independently used, or a suitablecombination thereof may be used. As the organic solvent, a solvent usedin the synthesis reaction of the phosphazene compound and left as it ismay be used, or a solvent newly added to the isolated phosphazenecompound may be used. Further, a solvent such as toluene, xylene,diethylketone, methoxybenzene, and cyclopentanone may be mixed within arange exerting no bad influence on the solubility in order to enhancethe easiness to apply.

Further, a 2,2′-hexafluoropropylidendiphthalate dianhydride, a2,3,3′,4′-biphenyltetracarboxylate dianhydride, or the acid dianhydriderepresented by the formula (1 1) or (12) is used as a main component ofthe acid dianhydride component, and aromatic diamine having an aminogroup in its m-position, diamine having a sulfonic group, orsiloxanediamine represented by the formula (12) is used as a part of thediamine component, thereby remarkably improving the solubility of theobtained soluble polyimide resin (D). Thus, it is possible to dissolvethe resultant in a solvent whose boiling point is low (120° C. or lower)e.g., an ether solvent such as dioxane, dioxolane, and tetrahydrofuran,and a halogen solvent such as chloroform and methylene chloride.Particularly, in case of applying/drying the photosensitive resincomposition, it is advantageous to use the solvent whose boiling pointis low (120° C. or lower) so as to prevent thermal polymerization whenacryl and/or methacryl are mixed.

As described above, the photosensitive resin composition is dissolved inthe organic solvent, so that it is possible to obtain the photosensitiveresin composition solution. Further, a thermosetting resin such as anepoxy resin and an acryl resin or a thermoplastic resin such aspolyester, polyamide, polyurethane, and polycarbonate may be mixed withthe photosensitive resin solution as required.

Instead of dissolution of the photosensitive resin composition in theorganic solvent, the photosensitive resin composition according to thepresent invention can be produced in a solution state. Examples thereofinclude dimethylsulfoxide, hexamethylphosphoamide, dimethylacetoamide,dimethylformamide, N-methyl-2-pyrrolidone, gammabutyrolactone, diglyme,butoxyethanol, propyleneglycolmethylethylacetate (PGMEA), toluene,xylene, dioxolane, tetrahydrofuran, methylethylketone, isopropylalcohol,and the like, but the photosensitive resin composition in the solutionstate is not limited to them. In order to realize uneven film thicknessof the photosensitive resin composition, adjust the thickness, andimprove the bonding property thereof, a mixture of two or more solventscan be used. In case of producing a heat-resistant photoresistcomposition by using the photosensitive resin composition, aphotosensitive resin composition solution is produced so as to haveconcentration ranging from 0.1 to 70 wt %, and coating thickness thereofis adjusted, thereby producing the heat-resistant photoresist.

[Usage of Photosensitive Resin Composition]

A usage of the photosensitive resin composition according to the presentinvention is not particularly limited, but a specific example thereof isa photosensitive resin film obtained by using the photosensitive resincomposition for example. The photosensitive resin composition can befavorably used as a print wiring board adhesive sheet, a photosensitivecover lay film, a print wiring board insulative circuit protection film,or a print wiring board substrate.

The photosensitive resin film is described as follows with a specificexample thereof.

The photosensitive resin composition solution is dried into a thin film,thereby producing the photosensitive resin film. It is possible to formthe thin film made of the photosensitive resin composition by adoptingany one of a spin coating process, a bar coating process, and a doctorblade process, which are widely carried out in an electronic field.

In forming the thin film made of the photosensitive resin composition,it may be so arranged that: the photosensitive resin compositionsolution is applied to a support made of metal, PET, or the like, andthe photosensitive resin composition is stripped away from the supportafter being dried, and the stripped photosensitive resin composition istreated as a film; or it may be so arranged that: the photosensitiveresin composition is used with it laminated on a film such as PET or thelike. A temperature at which the photosensitive resin compositionsolution is dried preferably ranges from 40° C. to 180° C., morepreferably from 40° C. to 150° C. When the drying temperature isexcessively low, the drying time is longer. It is not preferable thatthe drying temperature is excessively high since the heat causes theepoxy group and the unsaturated double bond/unsaturated triple bond tobe cross-linked and causes thermal decomposition.

As the photosensitive resin film, it is possible to use an FPCphotosensitive cover lay film for example. Generally, in the productionsteps of the FPC, an adhesive is applied to a long film, and the film isdried, and a copper foil is laminated thereon so that these steps aresequentially carried out. The production steps are excellent in terms ofthe productivity. However, as described above, it is necessary to formholes or windows on an uncombined cover lay film so as to correspond tojunctions of terminals or portions of the circuit, and the hole and thelike of the cover lay film are almost manually positioned so as tocorrespond to junctions of terminals or portions of the FPC, and thework size is small and the photosensitive cover lay film is combinedwith the FPC by a batch process, so that this is not preferable in termsof workability and positional accuracy. This results in increase of themanufacturing cost.

The photosensitive resin film according to the present invention can belaminated at temperature not more than 150° C., and the photosensitiveresin film can be laminated directly on the print substrate without anyadhesive. It is more preferable that a lamination temperature is lower.The lamination temperature is preferably 130° C. or lower, morepreferably 110° C. or lower. Further, in the photosensitive resin filmof the present invention, after combining the FPC with thephotosensitive resin film, exposure and development are carried out, sothat it is possible to form holes which allow connection with the FPCterminal sections, thereby improving the positional accuracy, theworkability, and the like. Thus, the photosensitive resin film of thepresent invention can be favorably used as an FPC photosensitive coverlay film.

In the production steps of the FPC, the FPC is exposed to hightemperature of 200° C. or higher in bonding parts and the like withsolder. Thus, it is preferable that the cured photosensitive resin filmcan resist higher temperature. Further, a thermal decompositiontemperature of the photosensitive resin film itself is preferably 300°C. or higher, more preferably 320° C. or higher, still more preferably340° C. or higher.

Further, an FPC conductive layer is made mainly of copper. In case wherethe copper is exposed to temperature exceeding 200° C., a crystalstructure of the copper gradually changes, and its strength drops. Thus,it is necessary to set the curing temperature to 200° C. or lower.

The step of combining the photosensitive resin film with the FPC isdescribed as follows. In this step, a conductor surface of the FPC whosecircuit is made of conductor such as a silver foil in advance isprotected by the photosensitive resin film. Specifically, the FPC andthe photosensitive resin film are made to overlap each other, and theyare combined with each other by heat lamination, heat press, or heatvacuum lamination. It is preferable that temperature for combining themis set so as not to cause the epoxy group or the unsaturated doublebond/unsaturated triple bond to be cross-linked or so as not to causethermal decomposition. Specifically, the temperature for combining ispreferably 180° C. or lower, more preferably 150° C. or lower, stillmore preferably 130° C. or lower.

Next, light is irradiated to the thin film made of the photosensitiveresin film via a photo mask having a predetermined pattern, therebyobtaining a desired pattern. The developing step may be carried out byusing a general positive photoresist developing device. In carrying outthe exposure, it is possible to use an exposing device for irradiatingvisible light or an ultraviolet ray whose wavelength ranges from 200 to500 nm, and it is advantageous to use an exposing device, provided witha filter preferably indicative of a monotone wavelength, in terms of theresolution and the workability. Further, the present invention is notlimited to a specific device or a specific exposing device.

Time required in exposure can be varied depending on an experimentalcondition. In the present invention, when an ultraviolet ray exposingdevice provided with a filter indicative of a wavelength of 365 nm isused, it is possible to vary the exposing time from 5 to 300 seconds. Byenhancing the exposure of the exposing device, it is possible to reducethe exposing time. A quantity of exposing energy is determined by anenergy gauge, and resolution is confirmed by a profile gauge in terms ofa depth and a width.

<Developer>

A developer used in the developing step is described as follows.

As the developer, a basic solution can be used. For example, as thedeveloper, an aqueous solution which is basic or a solution in which onekind of a basic compound is dissolved may be used, or a solution inwhich two or more kinds of basic compounds are dissolved may be used.Generally, the basic solution is a solution obtained by dissolving abasic compound in water. A concentration of the basic compound in thebasic solution preferably ranges from 0.1 to 50 weight/wt %, and morepreferably from 0.1 to 30 weight/wt % in terms of influence exerted onthe support substrate and the like. Note that, in order to improve thesolubility of the soluble polyimide resin (D), the developer maypartially include an aqueous organic solvent such as methanol, ethanol,propanol, isopropyl alcohol, N-methyl-2-pyrrolidone,N-methyl-2-pyrrolidone, N,N-dimethyl formamide, and N,N-dimethylacetamide.

Examples of the basic compound are alkaline metal, alkaline earth metalor ammonium ion hydroxide or carbonate, amine compound, and the like.Specific preferable examples thereof include 2-dimethylaminoethanol,3-dimethylamino-1-propanol, 4-dimethylamino-1-butanol,5-dimethylamino-1-pentanol, 6-dimethylamino-1-hexanol,2-dimethylamino-2-methyl-1-propanol,3-dimethylamino-2,2-dimethyl-1-propanol, 2-diethylaminoethanol,3-diethylamino-1-propanol, 2-diisopropylaminoethanol,2-di-n-butylaminoethanol, N,N-benzyl-2-aminoethanol,2-(2-dimethylaminoethoxy)ethanol, 2-(2-diethylaminoethoxy)ethanol,1-dimethylamino-2-propanol, 1-diethylamino-2-propanol,N-methyldiethanolamine, N-ethyldiethanolamine, N-n-butyldiethanolamine,N-t-butyldiethanolamine, N-lauryldiethanolamine,3-diethylamino-1,2-propanediol, triethanolamine, triisopropanolamine,N-methylethanolamine, N-ethylethanolamine, N-n-butylethanolamine,N-t-butylethanolamine, diethanolamine, diisopropanolamine,2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol,6-amino-1-hexanol, 1-amino-2-propanol, 2-amino-2,2-dimethyl-1-propanol,1-aminobutanol, 2-amino-1-butanol, N-(2-aminoethyl)ethanolamine,2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol,3-amino-1,2-propanediol, 2-amino-2-hydroxymethyl-1,3-propanediolamine,sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodiumcarbonate, potassium carbonate, ammonium carbonate, sodium hydrogencarbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate,tetramethylammoniumhydroxide, tetraethylammoniumhydroxide,tetrapropylammoniumhydroxide, tetraisopropylammoniumhydroxide,aminomethanol, 2-aminoethanol, 3-aminopropanol, 2-aminopropanol,methylamine, ethylamine, propylamine, isopropylamine, dimethylamine,diethylamine, dipropylamine, diisopropylamine, trimethylamine,triethylamine, tripropylamine, triisopropylamine, and the like. However,any other compound may be used as long as the compound is soluble inwater or the aqueous organic solvent such as alcohol and the solution isbasic.

The pattern formed through the development is subsequently rinsed with arinse liquid so as to remove the developer. Preferable examples of therinse liquid include methanol, ethanol, isopropyl alcohol, water, andthe like which are compatible with the developer.

The pattern bound in the foregoing process is subjected to heattreatment at temperature ranging from 20° C or higher to 200° C. orlower, thereby binding a resin pattern made of the photosensitive resinfilm of the present invention with high resolution. The resin patternhas high heat resistance and an excellent mechanical property. In theforegoing manner, it is possible to produce the FPC photosensitive coverlay film with the photosensitive resin film of the present invention.

Embodiment 2

The following description explains Embodiment 2 of the presentinvention. Note that, the present invention is not limited to this.

The photosensitive resin composition according to the present embodimentincludes at least the polyimide resins (G) and the phosphazene compound(H), and further includes (meth)acrylic compounds (I). Among them, asthe polyimide resins, the soluble polyimide resin (G-1) which has acarboxyl group and/or a hydroxyl group and is soluble in an organicsolvent is used. As the phosphazene compound (H), the phenoxyphosphazenecompound (H-1) having a phenolic hydroxyl group and/or the cross-linkedphenoxyphosphazene compound (G-2) obtained by cross-linking thephenoxyphosphazene compound (H-1) is used.

The photosensitive resin composition according to the present inventionuses the soluble polyimide resin (G-1) having a carboxyl group and/or ahydroxyl group. On this account, it is possible to give the heatresistance, the anti-bending property, the excellent mechanicalproperty, the electric insulation property, and the anti-chemicalproperty to the cured resin obtained by curing the photosensitive resincomposition (for example, the photosensitive resin film). Particularly,the soluble polyimide resin (G-1) has the carboxyl group and/or thehydroxyl group, so that it is possible to carry out the waterdevelopment of the photosensitive resin composition. Further, othercomponent (J) may be included as required. As the other component, forexample, it is possible to include a component which gives propertiessuch as the bonding property, the flame retardancy, the heat resistance,the anti-bending property to the photosensitive resin composition. Notethat, the photosensitive resin film according to the present embodimentis formed by using the photosensitive resin composition according to thepresent embodiment. The following details components thereof.

[Polyimide Resins (G)]

As the polyimide resins according to the present embodiment, at leastthe soluble polyimide resin (G-1) is used. The soluble polyimide resin(G-1) of the present embodiment has a carboxyl group and/or a hydroxylgroup in its side chain, and is soluble in the organic solvent. The“soluble polyimide resin” is a term given to such polyimide resin forease of description.

The soluble polyimide resin (G-1) is not particularly limited as long asthe resin is the polyimide resin defined in the foregoing manner.However, it is preferable that: the polyimide resin has a structureincluding at least one kind of an organic solvent solubility providingcomponent selected from an aliphatic compound component, an alicycliccompound component, and an alkylene oxide providing component of abisphenol compound.

<Soluble Polyimide Resin (G-1)>

As described above, the “soluble” of the soluble polyimide resin (G-1)means a condition under which the resin is soluble in an organicsolvent. More specifically, in the present invention, the “soluble”means a condition under which 1.0 g or more of the resin is dissolved in100 g of the organic solvent at 20° C. As to the solubility, it ispreferable that 1.0 g or more of the soluble polyimide resin (G-1) ofthe present invention is dissolved in the 100 g of the organic solventat 20° C., but it is more preferable that 5.0 g or more of the resin isdissolved in 100 g of the organic solvent at 20° C., and it is stillmore preferable that 10.0 g or more of the resin is dissolved in 100 gof the organic solvent at 20° C. In case where the solubility allowsless than 1 g of the resin to be dissolved in 100 g of the organicsolvent at 20° C., it is more difficult to form the photosensitive resinfilm so as to have a desired thickness in forming the photosensitiveresin film by using the photosensitive resin composition. The organicsolvent is not particularly limited, but examples thereof include: aformamide solvent such as N,N-dimethylformamide andN,N-diethylformamide; an ether solvent such as 1,4-dioxane,1,3-dioxolane, and tetrahydrofuran; and the like.

A weight-average molecular weight of the soluble polyimide resin (G-1)preferably ranges from 5000 to 200000, more preferably from 10000 to100000. When the weight-average molecular weight is less than 5000, thephotosensitive resin film produced by using the photosensitive resincomposition of the present invention is likely to be cloggy, and thecured photosensitive resin film is likely to be deteriorated in terms ofthe anti-bending property. While, when the weight-average molecularweight exceeds 200000, the solution of the soluble polyimide resin (G-1)has excessively high viscosity, so that it tends to be hard to treat theresultant. Further, the developing property of the producedphotosensitive resin film is likely to drop. Note that, theweight-average molecular weight can be measured by a size exclusionchromatography (SEC), for example, HLC8220GPC (product of TosohCorporation).

As the hydroxyl group of the soluble polyimide resin (G-1), it ispreferable to use a phenolic hydroxyl group. Further, a weight-averagemolecular weight of each carboxyl group and/or each hydroxyl group ofthe soluble polyimide resin (hereinafter, the weight-average molecularweight is referred to as an acid equivalent) is preferably 7000 or less,more preferably 5000 or less, most preferably 3000 or less. When theacid equivalent exceeds 7000, it is likely to be hard to carry out waterdevelopment of the photosensitive resin film produced by using thephotosensitive resin composition of the present invention. Note that, itis possible to obtain the acid equivalent of the soluble polyimide resin(G-1) by calculation based on a composition of the soluble polyimideresin (G-1).

Further, as will be described later, it is preferable that the solublepolyimide resin (G-1) of the present invention has at least one kind ofan unsaturated double bond, selected from an acryl group, a methacrylgroup, a vinyl group, and an allyl group, in its side chain. The solublepolyimide resin (G-1) has a photosensitive group such as the acrylgroup, the methacryl group, the vinyl group, and the allyl group in itsside chain, so that it is possible to improve a curing property of anexposed portion in exposing the photosensitive resin composition.

Note that, in the soluble polyimide resin (G-1), an acid dianhydridecomponent and a diamine component are used as monomer components servingas materials, and these monomer components are reacted with each other,thereby polymerizing a polyamide acid (polyamic acid). Further, theresultant is imidized, thereby obtaining the soluble polyimide resin.

Further, also in the present embodiment, a specific structure of thesoluble polyimide resin (G-1) is not particularly limited. However, asin Embodiment 1, an acid dianhydride and a diamine each of which has aspecific structure described later are used as the monomer components,so that it is possible to obtain the soluble polyimide resin (G-1) whichis more suitable for the photosensitive resin composition according tothe present invention. Note that, a production method of the solublepolyimide resin (G-1) will be described later.

<Acid Dianhydride Component>

In the soluble polyimide resin (G-1) favorably used in the presentinvention, the acid dianhydride serving as a material is notparticularly limited as long as the acid dianhydride is a carboxylatedianhydride having a carboxyl group. Further, in order to improve theheat resistance of the photosensitive resin composition, it ispreferable to use a carboxylate dianhydride having one to four aromaticrings or an alicyclic carboxylate dianhydride. Further, in order toimprove the solubility in the organic solvent, it is preferable to use acarboxylate dianhydride having two or more aromatic rings as at least apart of the photosensitive resin composition, and it is more preferableto use a carboxylate dianhydride having four or more aromatic rings asat least a part of the photosensitive resin composition.

Specific examples of a compound serving as the acid dianhydride include:aliphatic or alicyclic tetracarboxylate dianhydride such asbutanetetracarboxylate dianhydride and1,2,3,4-cyclobutanetetracarboxylate dianhydride; aromatictetracarboxylate dianhydride such as pyromellitic acid dianhydride,3,3′,4,4′-benzophenone tetracarboxylate dianhydride,3,3′,4,4′-biphenylsulfonete tracarboxylate dianhydride,2,2′-bis(hydroxyphenyl)propanedibenzoate)-3,3′,4,4′-tetracaboxylatedianhydride, 2,3(,3,4′-biphenylether tetracarboxylate dianhydride,3,4,3′,4′-biphenylethertetracarboxylate dianhydride, andbiphenyl-3,4,3′,4′-tetracarboxylate dianhydride; aliphatictetracarboxylate dianhydride such as1,3,3a,4,5,9b-hexahydro-2,5-dioxo-3-furanyl)-naptho[1,2-c]furan-1, and3-dione, and the like, but the acid dianhydride component is not limitedto them. The acid dianhydrides may be independently used, or a suitablecombination of two or more kinds may be used.

As the acid dianhydride, it is more preferable to use a part of the aciddianhydride, having two or more aromatic rings, such as2,2′-bis(4-hydroxyphenyl)propane dibenzoate-3,3′,4,4′-tetra carboxylatedianhydride, 2,3′,3,4′-biphenylether tetra carboxylate dianhydride,3,4,4′-biphenylether tetra carboxylate dianhydride, andbiphenyl-3,4,3′,4′-tetra carboxylate dianhydride. These compounds can beeasily synthesized, and each compound allows the obtained solublepolyimide resin (G-1) to have high solubility in the organic solvent.

<Diamine>

In the soluble polyimide resin (G-1) favorably used in the presentinvention, a diamine component serving as a material is not particularlylimited, but it is preferable to use a diamine having one or morecarboxyl groups and/or one or more hydroxyl groups in its molecule (forease of description, this diamine is referred to as a hydroxy diamine)as at least a part of the material in terms of the water development.Further, it is preferable to use an aromatic diamine having one or morearomatic tins in its molecule as at least a part of the material interms of the heat resistance and the anti-chemical property. Thus,particularly in case where an aromatic diamine having one or morecarboxyl groups and one or more hydroxyl groups in its molecule (forease of description, this diamine is referred to as a hydroxy aromaticdiamine) is used as a part of the material, it is possible to give theheat resistance and the water developing property to the photosensitiveresin film made of the photosensitive resin composition, so that use ofthe hydroxy aromatic diamine is more preferable.

The hydroxy aromatic diamine is not particularly limited as long as thediamine is an aromatic diamine having one or more carboxyl groups and/orone or more hydroxyl groups in its molecule, but it is preferable to useas a part of the material for the soluble polyimide resin (G-1) ahydroxy aromatic diamine represented by the following formula (19)

where R¹² represents a hydroxyl group or a carboxyl group, and R²² andR²³ may be different from each other, and each of R²² and R²³ representsa hydrogen atom, an alkyl group containing 1 to 9 carbon atoms, analcoxy group containing 2 to 10 carbon atoms, or COOR²⁴ (R²⁴ representsan alkyl group containing 1 to 9 carbon atoms), and X represents —O—,—S—, —SO₂—, —C(CH₃)₂—, —CH₂—, —C(CH₃)(C₂H₅)—, or C(CF₃)₂—, each of a andb is an integer not less than 0 so that a+b=4, and each of c and d is aninteger not less than 0 so that c+d=4, and e is an integer ranging from0 to 10.

Further, among the hydroxy aromatic diamines, the hydroxyl diaminehaving a carboxyl group is not particularly limited as long as thediamine has a carboxyl group. However, examples thereof include: diaminobenzoic acid such as 3,5-diamino benzoic acid; carboxy biphenylcompounds such as 3,3′-diamino-4,4′-dicarboxybiphenyl, 4,4′-diamino-2,2′,5,5′-tetracarboxybiphenyl; carboxydiphenyl alkanes such as4,4′-diamino-3,3′-dicarboxydiphenylmethane and3,3′-diamino-4,4′-dicarboxydiphenylmethane; carboxy diphenylethercompounds such as 4,4′-diamino-2,2′,5,5′-tetracarboxydiphenylether;diphenylsulfone compounds such as3,3′-diamino-4,4′-dicarboxydiphenylsulfone; bis(hydroxy phenoxy)biphenylcompounds such as 2,2-bis[4-(4-amino-3-carboxyphenyl)phenyl]propane;bis[(-carboxy phenoxy)phenyl]sulfone compounds such as 2,2-bis[4-(4-amino-3-carboxy phenoxy)phenyl]sulfone; and the like.

Further, a particularly preferable example of a hydroxy aromatic diaminehaving a carboxyl group is a hydroxy aromatic diamine represented by thefollowing formula (20).

Further, among the hydroxy aromatic diamines, the hydroxy aromaticdiamine having a hydroxyl group is not particularly limited as long asthe hydroxy aromatic diamine has a hydroxyl group. However, examplesthereof include: compounds such as 2,2′-diaminobisphenol A,2,2′-bis(3-amino-4-hydroxyphenyl)hexafluoropropane,bis(2-hydroxy-3-amino-5-methylphenyl)methane,2,6-di{(2-hydroxy-3-amino-5-methylphenyl)methyl}-4-methylphenol,2,6-di{(2-hydroxy-3-amino-5-methypphenyl)methyl}-4-hydroxybenzoic acidpropyl, and the like.

Further, a particularly preferable example of a hydroxy aromatic diaminehaving a hydroxyl group is a hydroxy aromatic diamine represented by thefollowing formula (21).

The hydroxy aromatic diamines may be independently used, or a suitablecombination of two or more kinds may be used. The hydroxy aromaticdiamine is used as a part of the material, so that the acid equivalentof the obtained soluble polyimide resin (G-1) drops, thereby improvingthe developing property with respect to the alkaline aqueous solution.

Not only the foregoing aromatic diamine but also other diamines may besimultaneously used as a part of the material. Specific examples ofother diamines include compounds such as bis [4-(3-aminophenoxy)phenyl]sulfone, reactive silicone (hereinafter, referred to assilicon diamine) having an amino group in each end of its siloxanestructure, [bis(4-amino-3-carboxy)phenyl]methane, and the like.Particularly, it is preferable to use silicon diamine since it ispossible to drop the elastic mudulus of the photosensitive resin film.Such other diamines may be independently used, or a suitable combinationof two or more kinds may be used.

<Synthesis of Soluble Polyimide Resin (C-1)>

It is possible to produce the soluble polyimide resin (G-1) used in thepresent in accordance with a known method. Specifically, it is possibleto produce the soluble polyimide resin (G-1) in accordance with a methodsimilar to the first method in Embodiment 1 for producing the solublepolyimide resin (E-1). That is, an acid dianhydride component and adiamine component are used as materials (monomer components), and thesemonomer components are polycondensed so as to synthesize a polyamideacid (polyamic acid) serving as a precursor, and the resultant ischemically or thermally subjected to dehydration cyclization(imidization). In this manner, these operations are performed in twosteps. Also in synthesizing and imidizing the polyamide acid, it ispossible to adopt a method similar to the first method.

Further, as the diamine component, for example, it is possible to use adiamine solution obtained by dissolving the diamine in an organicsolvent in the presence of inert atmosphere such as argon and nitrogenor obtained by dispersing the diamine in the organic solvent in a slurrymanner. Further, as the acid dianhydride component, for example, it ispossible to use a solution obtained by dissolving the acid dianhydridein the organic solvent or dispersing the acid anhydride in the organicsolvent in a slurry manner or it is possible to use the acid dianhydridein a solid phase.

<Soluble Polyimide Resin (G-1) having Unsaturated Double Bond>

Further, it is preferable that the soluble polyimide resin (G-1)according to the present invention is a soluble polyimide resin havingat least one kind of an unsaturated double bond, selected from an acrylgroup, a methacryl group, a vinyl group, a vinyl group, and an allylgroup, in its side chain (for ease of description, this solublepolyimide resin is referred to as a double bond polyimide resin). Thesoluble polyimide resin (G-1) has the unsaturated double bond, so thatit is possible to carry out cross-linking reaction of the solublepolyimide resin (G-1) and the (meth)acrylic compounds (I), or it ispossible to carry out cross-linking reaction of the soluble polyimideresins (G-1).

It is possible to obtain the double bond polyimide resin by reacting acompound having an unsaturated double bond with the soluble polyimideresin (G-1) and denaturalizing the resultant. The compound having theunsaturated double bond is not particularly limited as long as thecompound reacts with the carboxyl group and/or the hydroxyl grouppositioned in the side chain of the soluble polyimide resin (G-1).However, examples of the compound include: halogen allyl, having anunsaturated double bond, such as an epoxy compound, (meth)acrylateanhydride, and allyl bromide; and the like.

The reaction of the soluble polyimide resin (G-1) and the epoxy compoundhaving the unsaturated double bond can be carried out, for example, byreacting the soluble polyimide resin (G-1) with the epoxy compound in aninert solvent and in the presence of an organic base such as pyridine ortriethylamine. In this manner, it is possible to obtain the desireddouble bond polyimide resin.

It is preferable that a reaction temperature in the reaction is 40° C.or higher and 130° C. or lower at which the epoxy group reacts with thecarboxyl group and/or the hydroxyl group. Particularly, it is preferableto carry out the reaction at such temperature that heat does not causereaction such as polymerization of the unsaturated double bond.Specifically, the reaction temperature is more preferably 40° C. orhigher and 100° C. or lower, still more preferably 50° C. or higher and80° C. or lower. Further, reaction time is suitably set, but it ispreferable that the reaction time ranges from 1 hour to 20 hours.

A reaction solution obtained by the foregoing reaction may be used in asolution state after the reaction. Alternatively, it may be so arrangedthat: the compound is deposited in an alcohol solvent such as methanol,and the resultant is rinsed with the alcohol solvent as required.

The epoxy compound having an unsaturated double bond is not particularlylimited as long as the compound has an epoxy group and an unsaturateddouble bond in its molecule. However, examples thereof include glycidylacrylate, glycidyl methacrylate, allyl glycidyl ether, glycidyl vinylether, and the like. Among them, it is particularly preferable to useglycidyl methacrylate due to easiness to obtain at low cost and itsfavorable reactivity.

Next, an example of the reaction of the soluble polyimide resin (G-1)and the (meth)acrylate anhydride is reaction in which: a hydroxyl grouppositioned in the side chain of the soluble polyimide resin (G-1) andthe (meth)acrylate anhydride are condensed in an inert solvent. In thismanner, it is possible to obtain the desired double bond polyimideresin.

It is preferable that a reaction temperature in the reaction is 0° C. orhigher and 100° C. or lower at which the hydroxyl group positioned inthe side chain of the soluble polyimide resin (G-1) can be acylated.Particularly, it is preferable to carry out the reaction at suchtemperature that heat does not cause reaction such as polymerization ofthe unsaturated double bond. Specifically, the reaction temperature ismore preferably 10° C. or higher and 100° C. or lower, still morepreferably 20° C. or higher and 80° C. or lower. Further, reaction timeis suitably set, but it is preferable that the reaction time ranges from1 hour to 20 hours.

In order to remove the (meth)acryl acid generated by the foregoingreaction, it is preferable to treat the reaction solution obtained bythe reaction as follows: the compound is deposited in an alcohol solventsuch as methanol, and the compound is rinsed with the alcohol solvent asrequired.

Further, an example of the reaction of the soluble polyimide resin (G-1)and allyl halide is a reaction in which: the hydroxyl group positionedin the side chain of the soluble polyimide resin (G-1) and the allyhalide are reacted with each other in an inert solvent and in an organicbase such as pyridine or triethylamine. In this manner, it is possibleto obtain the desired double bond.

It is preferable that the reaction temperature is 0° C. or higher and100° C. or lower which allows reaction of the soluble polyimide resin(G-1) and the allyl halide. Particularly, it is preferable to carry outthe reaction at such temperature that heat does not cause reaction suchas polymerization of the unsaturated double bond. Specifically, thereaction temperature is more preferably 0° C. or higher and 80° C. orlower, still more preferably 20° C. or higher and 50° C. or lower. Thereaction time can be suitably set, but the reaction time preferablyranges from 1 hour to 20 hours.

It is preferable to treat the reaction solution obtained in theforegoing reaction by depositing the compound in an alcohol solvent suchas methanol and rinsing the resultant with the alcohol solvent asrequired.

In any one of the foregoing reactions, in order to keep the developingproperty with respect to the alkaline aqueous solution, it is preferablenot to react all the carboxyl groups and/or all the hydroxyl groups inthe side chain of the soluble polyimide resin (G-1) but to adjust anequivalent of the target compound having an unsaturated monomer so thatthe carboxyl groups and/or the hydroxyl groups remain. Specifically, itis necessary only to adjust an acid equivalent of the reacted doublebond polyimide resin to 7000 or less.

Further, in order to prevent the unsaturated double bond from beingpolymerized during the reaction, it is preferable to add apolymerization inhibitor. Examples of the polymerization inhibitorinclude a hydroquinone derivative such as p-methoxyphenol,phenothiazine, N-nitrohydroxylamine salts, and the like.

The soluble polyimide resin (G-1) obtained by introducing aphotopolymerizable group and/or a thermally polymerizable group such asthe unsaturated double bond in this manner has a favorable curingproperty and a favorable bonding property.

Note that, the double bond polyimide resin is arranged in any manner aslong as the soluble polyimide resin (G-1) has an unsaturated double bondin its side chain. That is, the unsaturated double bond of the solublepolyimide resin (G-1) is not limited to the foregoing functional groups,and the soluble polyimide resin (G-1) may have a functional group havingan unsaturated double bond other than the foregoing functional groups.

[Phosphazene Compound (H)]

In the photosensitive resin composition according to the presentinvention, a compound having a phenolic hydroxyl group, that is, thephenoxyphosphazene compound (H-1) and/or the cross-linkedphenoxyphosphazene compound (G-2) are used. The cross-linkedphenoxyphosphazene compound (G-2) is a phosphazene compound obtained bycross-linking the phenoxyphosphazene compound (H-1).

The phenoxyphosphazene compound (H-1) and/or the cross-linkedphenoxyphosphazene compound (G-2) are included, so that it is possibleto give the flame retardancy without losing the heat resistance of theobtained photosensitive resin composition. Particularly, the phosphazenecompound used in the present invention has a phenolic hydroxyl group inits molecule, so that it is possible to remarkably improve thecompatibility with the soluble polyimide resin (G-1) due to influence ofthe phenolic hydroxyl group. Thus, in the obtained photosensitive resincomposition, it is possible to suppress deposition (bleeding or juicing)of the flame retardant on the surface, thereby further improving theflame retardancy.

Moreover, the phenolic hydroxyl group is included in the molecule, sothat the phosphazene compound allows formation of a mesh structure byreacting particularly with an epoxy resin component (described later) incuring the photosensitive resin composition. Thus, efficient curing ispossible, thereby obtaining a cured product having excellent heatresistance. Further, it is also possible to improve alkaline solubilitycompared with the conventional phosphazene compound.

<Phenoxyphosphazene Compound (H-1)>

The phenoxyphosphazene compound (H-1) used in the present invention isnot particularly limited as long as the compound is a phosphazenecompound having a phenolic hydroxyl group. Specifically, it ispreferable to use at least one of a circular phenoxyphosphazene compound(G-11) and a chain phenoxyphosphazene compound (G-12).

Structures, properties, production methods, and the like of the circularphenoxyphosphazene compound (G-11) and the chain phenoxyphosphazenecompound (G-12) are the same as those of the circular phenoxyphosphazenecompound (A-11) and the chain phenoxyphosphazene compound (A-12) inEmbodiment 1.

<Cross-Linked Phenoxyphosphazene Compound (G-2)>

As described above, the cross-linked phenoxyphosphazene compound (G-2)has at least one phenolic hydroxyl group, and is a phosphazene compoundobtained by cross-linking the phenoxyphosphazene compound (H-1). Thecross-linked phenoxyphosphazene compound (G-2) may be obtained bycross-linking the phenoxyphosphazene compound (H-1) in accordance with aknown method, but it is preferable to cross-link the phenoxyphosphazenecompound (H-1) with a phenylene cross-linking group.

Any cross-linking group may be used as the phenylene cross-linking groupas long as a phenyl group is included in a structure, but it is possibleto use the same cross-linking group as that in Embodiment 1.

Further, also in the present embodiment, in case of synthesizing(producing) the cross-linked phenoxyphosphazene compound (G-2), anycompound may be used as the phenoxyphosphazene compound, but it ispreferable to use the circular phenoxyphosphazene compound (G-11) and/orthe chain phenoxyphosphazene compound (G-12). At this time, it ispreferable to use the phenylene cross-linking group as the cross-linkinggroup.

Further, as in Embodiment 1, in case where (1) the circularphenoxyphosphazene compound (G-11) and/or the chain phenoxyphosphazenecompound (G-12) are used as the phenoxyphosphazene compounds and (2) thephenylene cross-linking group is used as the cross-linking group, whenthese conditions are satisfied, it is preferable to define across-linking condition so as to satisfy the following conditions (3)and (4).

That is, it is preferable that: (3) the phenylene cross-linking groupintervenes between two oxygen atoms of the phenoxyphosphazene compound(H-1) (the circular phenoxyphosphazene compound (G-11) and/or the chainphenoxyphosphazene compound (G-12)) which are obtained by desorbing aphenyl group and a hydroxyphenyl group, and (4) a ratio at which phenylgroups and hydroxyphenyl groups are included in the cross-linkedphenoxyphosphazene compound ranges from 50 to 99.9% with respect to atotal of phenyl groups and hydroxyphenyl groups of the foregoingphenoxyphosphazene compound.

When the cross-linked phenoxyphosphazene compound (G-2) satisfying theconditions (1) to (4) is used, it is possible to further improve theflame retardancy of the heat-resistance resin composition. Note that,the cross-linked phenoxyphosphazene compound satisfying the conditions(1) to (4) is referred to as phenylene cross-linked phenoxyphosphazenecompounds.

<Example of Synthesis (Production) of Cross-linked PhenoxyphosphazeneCompound (G-2)>

A production method of the cross-linked phenoxyphosphazene compound(G-2) is not particularly limited, but it is possible to produce thecross-linked phenoxyphosphazene compound (G-2) in the same manner as inEmbodiment 1.

Note that, also in the present embodiment, an amount of thephenoxyphosphazene compound (inclusive the cross-linked compound)blended is not particularly limited. However, with respect to 100 partsby weight (total weight) of the soluble polyimide resin (G-1) and the(meth)acrylic compounds (I) described later, the amount preferablyranges from 1 to 100 parts by weight, more preferably from 1 to 50 partsby weight, particularly preferably from 1 to 40 parts by weight.

When the amount of the phenoxyphosphazene compound used is less than 1part by weight with respect to 100 parts by weight (total weight) of thesoluble polyimide resin (G-1) and the (meth)acrylic compounds (I), itmay be impossible to obtain a sufficient flame retardant effect. While,when the amount exceeds 100 parts by weight with respect to 100 parts byweight (total weight), the half-cured photosensitive dry film resist (ina B stage state) may be cloggy, and the resin may exude at the time ofthermal pressure. Moreover, this may have a bad influence on propertiesof the cured product. Thus, it is not preferable that the amount exceeds100 parts by weight.

[(Meth)acrylic Compounds' (I)]

Next, the (meth)acrylic compounds (I) are described as follows. Thephotosensitive resin composition according to the present inventionincludes the (meth)acrylic compounds (I), so that it is possible notonly to give a favorable curing property but also to give fluidity atthe time of thermal lamination by dropping the viscoelasticity of thephotosensitive resin film made of the photosensitive resin compositionat the time of heat treatment. That is, it is possible to carry out thethermal lamination at relatively low temperature, so that indentedportions of a circuit can be embedded therein.

In the present invention, the (meth)acrylic compounds (I) are compoundselected from a (meth)acryl compound, epoxy(meth)acrylate,polyester(meth)acrylate, urethane(meth)acrylate, andimide(meth)acrylate. Note that, in the present invention, (meth)acrylmeans acryl and/or methacryl.

The (meth)acrylic compounds may be independently used, or a suitablecombination of two or more kinds may be used. In the present invention,a total weight of the (meth)acrylic compounds (I) included in thephotosensitive resin composition of the present invention preferablyranges from 1 to 100 parts by weight, more preferably from 1 to 80 partsby weight, still more preferably from 1 to 50 parts by weight, withrespect to 100 parts by weight of the soluble polyimide resin (G-1).

In case where the (meth)acrylic compounds (I) whose amount exceeds 100parts by weight with respect to 100 parts by weight of the solublepolyimide resin (G-1), the heat resistance of the photosensitive resinfilm made of the obtained photosensitive resin composition drops, sothat the (meth)acrylic compounds (I) may exude at the time of thethermal lamination.

As the (meth)acrylic compounds (I) used in the photosensitive resincomposition of the present invention, particularly, it is preferable touse a (meth)acrylic compounds (I) having one or more epoxy groups andone or more (meth)acryl groups in its molecule. By using such(meth)acrylic compounds (I), it is possible to improve theanti-hydrolysis property of the photosensitive resin film made of theobtained photosensitive resin composition and the bonding strength withrespect to a copper foil.

The (meth)acrylic compounds (I) having one or more epoxy groups and oneor more (meth)acryl groups in its molecule are not particularly limited,but examples thereof include: a glycidyl compound such as glycidylmethacrylate; and epoxy acrylate such as NK NK oligo EA-1010 and EA-6310(each of which is a commercial name) produced by SHIN-NAKAMURA CHEMICALCO., LTD.

Further, as the (meth)acrylic compounds (I) used in the photosensitiveresin composition of the present invention, it is preferable toadditionally use epoxy (meth)acrylate having two or more hydroxyl groupsin its molecule, and it is more preferable to use epoxy (meth)acrylatehaving four or more hydroxyl groups in its molecule. Such epoxy(meth)acrylate is used, so that the solubility of the photosensitiveresin film made of the photosensitive resin composition is improved,thereby realizing shorter developing time.

The epoxy(meth)acrylate having two or more hydroxyl groups in itsmolecule is not particularly limited, but examples thereof include:bisphenol A type epoxy acrylate such as LIPOXY SP-2600 (commercial name:product of Showa Highpolymer Co., Ltd.), NK oligo EA-1020 and NK oligoEA-6340 (both of which are commercial names: products of SHIN-NAKAMURACHEMICAL CO., LTD.), KARAYAD R-280 and KARAYAD R-190 (both of which arecommercial names: products of Nippon Kayaku Co., Ltd.), and Ebercryl 600and Ebercryl 3700 (both of which are commercial names: products ofDAICEL-UCB Company LTD.); denaturalized bisphenol A type epoxy acrylatesuch as Ebercryl 3200, Ebercryl 3500, Ebercryl 3701, and Ebercryl 3703(all of which are commercial names: products of DAICEL-UCB CompanyLTD.); phenolnovolak epoxy acrylate such as NK oligo EA-6320 and NKoligo EA-6340; denaturalized 1,6-hexanediol acrylate such as KARAYADR-167 and MAX-2104 (both of which are commercial names: products ofNippon Kayaku Co., Ltd.), and denacol acrylate DA-212 (commercial name:Nagase Chemical Industries Co., Ltd.); denaturalized phthalatediacrylate such as denacol acrylate DA-721 (commercial name: product ofNagase Chemical Industries Co., Ltd.); cresol novolak epoxy acrylatesuch as NK oligo EA-1020 (commercial name: product of SHIN-NAKAMURACHEMICAL CO., LTD.); and the like.

In the photosensitive resin composition used in the present invention,it is possible to use not only the epoxy (meth)acrylate and the(meth)acrylic compounds having one or more epoxy groups and one or more(meth)acryl groups in its molecule but also polyester(meth)acrylate,urethane(meth)acrylate, imide(meth)acrylate, and other (meth)acryliccompound.

By using polyester(meth)acrylate, it is possible to give the flexibilityto the photosensitive resin film made of the obtained photosensitiveresin composition. The polyester(meth)acrylate is not particularlylimited, but examples thereof include ARONIX M-5300, ARONIX M-6100, andARONIX M-7100 (all of which are commercial names: product of TOAGOSEICO., LTD.), and the like.

By using urethane(meth)acrylate, it is possible to give the flexibilityto the photosensitive resin film made of the obtained photosensitiveresin composition. The urethane(meth)acrylate is not particularlylimited, but examples thereof include ARONIX M-1100 and ARONIX M-1310(both of which are commercial names: products of TOAGOSEI CO., LTD.),KARAYAD UX-4101 (commercial name: product of Nippon Kayaku Co., Ltd.),and the like.

By using imide(meth)acrylate, it is possible to improve the adhesivenessof the base material (polyimide film, copper foil, and the like) withwhich the photosensitive resin film made of the obtained photosensitiveresin composition is combined. The imide (meth)acrylate is notparticularly limited, but examples thereof include ARONIX TO-1534,ARONIX TO-1429, and ARONIX TO-1428 (all of which are commercial names:products of TOAGOSEI CO., LTD.).

Further, other(meth)acrylic compound is not particularly limited.However, in order to improve cross-linked density based on lightemission which will be described later, it is preferable to use amultifunctional (meth)acrylic compound having at least two unsaturateddouble bonds. Further, in order to give the heat resistance to thephotosensitive resin film made of the obtained photosensitive resincomposition, it is preferable to use a (meth)acrylic compound having atleast one aromatic ring and/or one heterocycle in its molecule.

The (meth)acrylic compound having at least one aromatic ring and/or oneheterocycle in its molecule and having at least two unsaturated doublebonds is not particularly limited, but examples thereof include:bisphenol A EO denaturalized di(meth)acrylate such as ARONIX M-210 andARONIX M-211B (both of which are commercial names: products of TOAGOSEICO., LTD.), NK ester ABE-300, NK ester A-BPE-4, NK ester A-BPE-10, NKester A-BPE-20, NK ester A-BPE-30, NK ester BPE-100, and NK esterBPE-200 (all of which are commercial names: products of SHIN-NAKAMURACHEMICAL CO., LTD.); bisphenol F EO denaturalized (n=2 to 20)di(meth)acrylate such as ARONIX M-208 (commercial name: product ofTOAGOSEI CO., LTD.); bisphenol A PO denaturalized (n=2 to 20)di(meth)acrylate such as denacol acrylate DA-250 (commercial name:Nagase Chemical Industries Co., Ltd.) and BISCOAT #540 (commercial name:product of Osaka Organic Chemical Industry Ltd.); phthalate POdenaturalized diacrylate such as denacol acrylate DA-721 (commercialname: Nagase Chemical Industries Co., Ltd.); and the like. Further, asthe (meth)acrylic compound having no aromatic ring, for example, it ispossible to use: isocyanuric acid EO denaturalized diacrylate such asARONIX M-215 (commercial name: product of TOAGOSEI CO., LTD.); andisocyanuric acid EO denaturalized triacrylate such as ARONIX M-315(commercial name: product of TOAGOSEI CO., LTD.) and NK ester A-9300.Note that, the “EO denaturalized” means that there is an ethylene oxidedenaturalized portion, and the “PO denaturalized” means that there is apropylene oxide denaturalized portion.

Among the (meth)acrylic compounds, it is particularly preferable to usea (meth)acrylic compound in which the number of recurring units(—(CH₂CH₂O)—) of an ethylene oxide denaturalized (EO denaturalized)portion in its molecule or the number of recurring units(—(CH(CH₃)CH₂O)—) of a propylene oxide denaturalized (PO denaturalized)portion in its molecule is 10 or more. Due to 10 or more recurring unitsdescribed above, it is possible to give thermal fluidity to thephotosensitive resin film made of the obtained photosensitive resincomposition at the time of lamination, thereby improving the solubilitywith respect to the alkaline aqueous solution.

The (meth)acrylic compound having 10 or more recurring units of an EOdenaturalized portion in its molecule or 10 or more recurring units of aPO denaturalized portion in its molecule is not particularly limited,but examples thereof include: bisphenol A EO denaturalizeddi(meth)acrylate such as NK ester A-BPE-10, NK ester A-BPE-20, NK esterA-BPE-30, NK ester A-BPE-100, and NK ester A-BPE-200 (all of which arecommercial names: products of SHIN-NAKAMURA CHEMICAL CO., LTD.);bisphenol F EO denaturalized (n=10 to 20) di(meth)acrylate; bisphenol APO denaturalized (n=10 to 20) di(meth)acrylate; and the like.

With respect to a total weight of all the (meth)acrylic compounds (I)contained in the photosensitive resin composition of the presentinvention, an amount of the (meth)acrylic compound having 10 or morerecurring units of an EO denaturalized portion in its molecule or 10 ormore recurring units of a PO denaturalized portion in its molecule ispreferably at least 10 parts by weight, more preferably 20 parts byweight or more.

[Other Component (J)]

The photosensitive resin composition of the present embodiment mayinclude not only the soluble polyimide resin (G-1), thephenoxyphosphazene compound (H-1), and the (meth)acrylic compounds (I),but also other component (J). Examples of other component (J) include anepoxy resin (J-1), a curing promotion agent and/or curing agent (J-2),and a photoreaction initiator and/or sensitizer (J-3).

<Epoxy Resin (J-1)>

The photosensitive resin composition of the present invention containsthe epoxy resin (J-1), so that it is possible to improve adhesiveness ofthe photosensitive resin film, made of the photosensitive resincomposition, with respect to a copper foil, a polyimide film, and thelike.

The epoxy resin is not particularly limited, but examples thereofinclude: a bisphenol A type epoxy resin such as Epikote 828, 834, 1001,1002, 1003, 1004, 1005, 1007, 1010, and 1100L (all of which arecommercial names: products of Japan Epoxy Resins Co., Ltd.); abrominated bisphenol A type epoxy resin such as Epikote 5050, 5051, and5051H (all of which are commercial names: products of Japan Epoxy ResinsCo., Ltd.); an o-cresolnovolak-type epoxy resin such as ESCN-220L, 220F,220H, 220HH, 180H65, and 180S65 (all of which are commercial names:products of Japan Epoxy Resins Co., Ltd.); a novolak type epoxy resinsuch as 1032H60 (commercial name: product of Japan Epoxy Resins Co.,Ltd.: trihydroxyphenylmethanenovolak type), EPPN-502H (commercial name:product of Nippon Kayaku Co., Ltd.: trihydroxyphenylmethanenovolaktype), ESN-375 and ESN-185 (both of which are commercial names: productsof Nippon Steel Chemical Group: naphthalenearalkylnovolak type), and157S70 (commercial name: product of Japan Epoxy Resins Co., Ltd.:bisphenol A novolak type); bisphenol type epoxy resin such as YX4000H(commercial name: product of Japan Epoxy Resins Co., Ltd.); and thelike.

Further, it is possible to use not only the foregoing resins but also abisphenol A glycidyl ether type epoxy resin, a bisphenol F glycidylether type epoxy resin, novolak glycidyl ether type epoxy resin, aglycidyl ester type epoxy resin, a glycidyl ester type epoxy resin, aglycidyl amine type epoxy resin, a cyclic fatty epoxy resin, an aromaticepoxy resin, a halogenous epoxy resin, and the like.

As the epoxy resin (J-1) included in the photosensitive resincomposition of the present invention, a suitable combination of two ormore kinds selected from the foregoing epoxy resins may be used. Notethat, with respect to 100 parts by weight of the soluble polyimide resin(G-1), an amount of the epoxy resin (J-1) preferably ranges from 1 to100 parts by weight as required, more preferably from 1 to 50 parts byweight, particularly preferably from 2 to 30 parts by weight. When theamount of the epoxy resin is less than 1 part by weight with respect to100 parts by weight of the soluble polyimide resin (G-1), theadhesiveness of the obtained photosensitive resin film drops. While,when the amount of the epoxy resin (J-1) exceeds 100 parts by weight,this may cause the heat resistance of the photosensitive resin film todrop and may cause the photosensitive resin film to be susceptible todamage upon being bent.

<Curing Promotion Agent/Curing Agent (J-2)>

In case where the epoxy resin (J-1) is used as a material of thephotosensitive resin composition of the present invention, a curingpromotion agent and/or a curing agent (J-2) may be added to thephotosensitive resin composition in order to efficiently cure thephotosensitive resin film made of the photosensitive resin composition.The curing promotion agent and/or the curing agent (J-2) is notparticularly limited. However, examples thereof include imidazolecompounds, acid anhydride, tertiary amines, hydrazines, aromatic amines,phenols, triphenylphosphins, organic peroxide, and the like. Among thesecuring promotion agents and/or the curing agents (J-2), one kind or acombination of two or more kinds is used.

With respect to 100 parts by weight of the soluble polyimide resin(G-1), an amount of the curing promotion agent and/or the curing agent(J-2) preferably ranges from 0.1 to 20 parts by weight, more preferablyfrom 1 to 20 parts by weight, particularly preferably from 1 to 15 partsby weight. When the amount of the curing promotion agent and/or thecuring agent (J-2) is less than 0.1 part by weight with respect to 100parts by weight of the soluble polyimide resin (G-1), the epoxy resin(J-1) is not sufficiently cured. Adversely, when the amount exceeds 20parts by weight, this may cause the heat resistance to drop.

<Photoreaction Initiator/Sensitizer (J-3)>

Further, it is preferable that the photosensitive resin composition ofthe present invention includes the photoreaction initiator and/or asensitizer (J-3). In case where the photosensitive resin film made ofthe photosensitive resin composition obtained by adding thephotoreaction initiator and/or the sensitizer (J-3) is exposed, it ispossible to promote the cross-linking reaction or the polymerizationreaction in an exposed area. On this account, it is possible tosufficiently differentiate the exposed area from an unexposed area interms of the solubility of the photosensitive resin film with respect tothe alkaline aqueous solution. As a result, it is possible to favorablydevelop a pattern on the photosensitive resin film.

Examples of the photoreaction initiator include a radical generationagent, a photocation generation agent, a photobase generation agent,photoacid generation agent, and the like.

As the radical generation agent, it is preferable to use an agent whichgenerates a radical based on light whose wavelength is as long as ag-line. Examples thereof include: ketone compound such as2,2-dimethoxy-1,2-diphenylethane-1-one and2-hydroxy-2-methyl-1-phenyl-propane-1-one; phosphin oxide compound suchas bis(2,4,6-trimethyl benzoyl)-phenylphosphinoxide andbis(2,6-dimethoxy benzoyl)-2,4,4-trimethyl-penthylphosphinoxide;titanocen compound such asbis(2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium;and the like, but the radical generation agent is not limited to them.Among these compounds, it is particularly preferable to use a phosphinoxide compound or a titanocen compound.

Further, examples of the photocation generation agent include diphenyliodonium saline such as diphenyl iodonium salt of dimethoxyanthraquinone sulphone; triphenyl sulphonium saline; pyrylinium saline;triphenyl onium saline; diazonium; and the like, but the photocationgeneration agent is not particularly limited. Note that, not only theforegoing saline but also an alicyclic epoxy or vinyl ether compoundhaving a high cation-curing property may be mixed.

Further, examples of the photobase generation agent include: abenzylalcohol-urethane compound obtained by reacting nitro benzylalcoholor dinitro benzylalcohol with isocyanate; a phenylalcohol-urethanecompound obtained by reacting nitro-1-phenylethylalcohol ordinitro-1-phenylethylalcohol with isocyanate; a propanol-urethanecompound obtained by reacting dimethoxy-2-phenyl-2-propanol withisocyanate; and the like, but the photobase generation agent is notparticularly limited.

Further, examples of the photoacid generation agent include: a compoundwhich allows generation of sulfonic acid such as iodonium salt,sulfonium salt, and onium salt; a compound which allows generation ofcarboxylic acid such as naphthoquinone diazide; and the like, but thephotoacid generation agent is not particularly limited. Further, it ispreferable to use compounds such as diazonium salt andbis(trichloromethyl)triazine because each of these compounds allowsgeneration of a sulfone group in response to irradiation of light.

While, the sensitizer is not particularly limited, but examples thereofinclude Michler's ketone, bis-4,4′-diethylamino benzophenone,3,3′-carbonylbis(7-diethylamino)coumarin, 2-(p-dimethylaminostyryl)quinoline, 4-(p-dimethylamino styryl)quinoline, and the like.

The photoreaction initiators and/or the sensitizers (J-3) may beindependently used, or a combination of two or more kinds may be used.

With respect to 100 parts by weight (total weight) of the solublepolyimide resin (G-1) and the (meth)acrylic compounds (I), an amount ofthe photoreaction initiator and/or the sensitizer (J-3) preferablyranges from 0.001 to 10 parts by weight, more preferably from 0.01 to 10parts by weight. When the amount of the photoreaction initiator and/orthe sensitizer (J-3) is less than 0.001 parts by weight with respect to100 parts by weight (total weight) of the soluble polyimide resin (G-1)and the (meth)acrylic compounds (I), or when the amount exceeds 10 partsby weight, it is impossible to obtain the sensitization effect, so thatthis may have bad influence on the developing property.

Further, in case of using the radical generation agent as thephotoreaction initiator and the sensitizer in combination, it ispossible to favorably use a combination of (i) peroxide such asbis(2,4,6-trimethyl benzoyl)phenylphosphinoxide and (ii)3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone.

[Photosensitive Resin Composition]

The photosensitive resin composition according to the present inventionincludes at least the soluble polyimide resin (G-1), thephenoxyphosphazene compound (H-1), and/or the cross-linkedphenoxyphosphazene compound (G-2) obtained by cross-linking thephenoxyphosphazene compound (H-1), and the (meth)acrylic compounds (I).The photosensitive resin composition preferably further includes othercomponent (J).

<Production of Photosensitive Resin Composition>

The production (preparation) method of the photosensitive resincomposition according to the present invention, that is, the method forblending the foregoing components is not particularly limited. However,an example thereof is a method in which the components are dissolved inan organic solvent capable of favorably dissolving the components so asto obtain a solution of the photosensitive resin composition. Morespecifically, for example, it may be so arranged that the components areadded to a proper solvent and the resultant is stirred so as to obtainthe solution of the photosensitive resin composition, or it may be soarranged that the components are dissolved respectively in propersolvents as preparation of solutions respectively corresponding to thecomponents and the thus obtained solutions are mixed with each other.

As the organic solvent used in this case, a known organic solvent usedas polyimide resin solvents can be used. Specific examples thereofinclude organic solvents such as aromatic hydrocarbon, ketones, esters,ethers (circular ethers, glycol ethers, and the like), N-substitutedamides, alcohols, carboxylic acids, amines, chlorine solvent, and thelike. Note that, the organic solvent is removed in subsequent steps, sothat it is advantageous in the production steps to select a solventwhich dissolves components included in the photosensitive resincomposition and whose boiling point is as low as possible. Particularly,it is possible to favorably use an organic solvent whose boiling pointis 170° C. or lower, preferably 160° C. or lower.

Specific examples of the organic solvent having the foregoing boilingpoint include: circular ether such as tetrahydrofuran, dioxolane, anddioxane; ethers such as ethyleneglycol dimethylether, triglime,diethylglycol, ethyl cellosolve, methyl cellosolve, diethylether, andchain ether such as various propyleneglycolethers; alcohols such asmethanol, ethanol, isopropyl alcohol, and butanol; ketones such asacetone, methylethylketone, and methylisobutylketone; cycloalkanes suchas cyclopentanone and cyclohexanone; esters such as acetic ether; andthe like. Further, it is possible to favorably use a mixture solventobtained by mixing toluene, xylenes, glycols, N,N-dimethyl formamide,N,N-dimethyl acetamide, N-methyl pyrrolidone, circular siloxane, chainsiloxane, and the like with the ethers. These organic solvents may beindependently used, or a suitable combination of two or more kinds maybe used.

<Usage of Photosensitive Resin Composition>

The usage of the photosensitive resin composition according to thepresent invention is not particularly limited. However, examples thereofinclude a photosensitive resin film or a photosensitive resin sheet anda resin chemical product each of which is made of the photosensitiveresin composition.

The photosensitive resin film is obtained by forming the photosensitiveresin composition into a film shape. It is possible to use thephotosensitive resin film, for example, as a pattern circuit resist filmused in formation of a pattern circuit, a photosensitive cover lay filmused in formation of an insulative protection film, a photosensitive dryfilm resist used in formation of an interlayer insulation layer, or forother various purposes, but the usage thereof is not limited to them.Further, the photosensitive resin film is arranged so as to correspondto usage thereof.

Note that, in the present invention, the photosensitive resin films usedas the photosensitive cover lay film and the photosensitive dry filmresist are generically referred to as a photosentive dry film resist.

Further, an example of the usage of the present invention is a laminatewhich includes at least one resin layer made of (i) the photosensitiveresin composition or (ii) a photosensitive resin film or aphotosensitive resin chemical product using the photosensitive resincomposition. The laminate can be favorably used, for example, as acircuit substrate or a multi-layered print wiring board.

The photosensitive resin composition according to the present inventioncan be used as a resin chemical product in the aforementioned solutionstate. Other various kinds of solvents and additives may be addedthereto as required, and the resultant may be used as the resin chemicalproduct. The resin chemical product including the photosensitive resincomposition according to the present invention can be used as a coatingagent or varnish. The resin chemical product can be impregnated intovarious fibers such as a glass cloth, a glass mat, an aromatic polyamidefiber cloth, and an aromatic polyamide fiber mat for example. When thephotosensitive resin composition impregnated into the fiber ishalf-cured, it is possible to obtain a fiber reinforced resin sheet.

Further, when the photosensitive resin composition according to thepresent invention is formed in a sheet shape in advance, it is possibleto use the photosensitive resin composition as the photosensitive resinfilm or the photosensitive resin sheet. Specific examples thereofinclude (1) a single-layer sheet made only of the photosensitive resincomposition, (2) a two-layer or three-layer sheet obtained by providinga resin layer made of the photosensitive resin composition on one sideor each side of a film used as a base material (film base material), and(3) a laminate such as a multi-layered sheet or the like in which filmbase materials and resin layers made of the photosensitive resincomposition are alternately stacked.

Next, the photosensitive resin film is specifically described as followsby taking the photosensitive dry film resist as an example, and anexample of a print wiring board produced by using the photosensitive dryfilm resist is specifically described as follows. However, the presentinvention is not limited to this.

<Photosensitive Dry Film Resist>

The photosensitive dry film resist is produced by evenly applying anddrying the organic solvent solution of the photosensitive resincomposition on a support film. After evenly applying and drying theorganic solvent solution of the photosensitive resin composition on thesupport film, the resultant is heated or is blasted by hot air. On thisaccount, the organic solvent is removed, so that it is possible toobtain the photosensitive dry film resist which is a film-shapedphotosensitive resin composition. The photosensitive dry film resistformed in this manner is a half-cured photosensitive resin composition(in a B stage state). Therefore, in case of carrying outthermocompression bonding such as thermal lamination, the photosensitivedry film resist can exhibit proper fluidity. On this account, it ispossible to favorably mount the pattern circuit of the print wiringboard. Further, after mounting the pattern circuit, an exposure process,a thermocompression bonding process, and heating cure are carried out,thereby completely curing the mounted pattern circuit.

A drying temperature at which the organic solvent solution of thephotosensitive resin composition is dried by heating and/or blastingwith hot air is set so that curing groups such as a (meth)acryl groupand an epoxy group included in the photosensitive resin compositionreact with each other. Specifically, the drying temperature ispreferably 120° C. or lower, particularly preferably 100° C. or lower.Further, it is preferable to set a drying time to be shorter as long asthe organic solvent can be removed within the drying time.

A material for the support film is not particularly limited, but it ispossible to use various kinds of ordinarily available films such as apolyethylene terephthalate (PET) film, a polyphenylene sulfide film, anda polyimide film. Among the foregoing support films, the PET film iswidely used since the PET film has proper heat resistance and can beobtained at relatively low cost. Note that, in a junction between thesupport film and the photosensitive dry film resist, it is possible tocarry out surface treatment in order to improve the adhesiveness andfissility.

Further, thickness of the support film is not particularly limited, butpreferably ranges from 5 μm to 50 μm, more preferably from 10 μm to 30μm. When the thickness of the support film is less than 5 μm, thesupport film wrinkles, so that the operability is likely to drop.Therefore, the support film with the thickness of less than 5 μm is notpreferable. Further, when the thickness of the support film exceeds 50μm, it is difficult to wind the photosensitive dry film resist.Therefore, the support film with the thickness exceeding 50 μm is notpreferable.

Further, it is preferable to laminate a protective film on thephotosensitive dry film resist produced by applying the organic solventsolution of the photosensitive resin composition on the support film.The protective film is laminated, so that it is possible to preventforeign substances and dusts in the air from adhering thereto and it ispossible to prevent the quality of the photosensitive dry film resistfrom being dropped by the drying.

It is preferable to laminate the protective film on the surface of thephotosensitive dry film resist at a temperature ranging from 10° C. to50° C. Note that, when the temperature at which the lamination iscarried out exceeds 50° C., the protective film thermally expands, sothat the laminated protective film may be wrinkled and curled.

The protective film is exfoliated in using the photosensitive dry filmresist, so that a junction between the protective film and the dry filmresist preferably has proper adhesiveness at the time of storage andexcellent fissility.

A material for the protective film is not particularly limited, butexamples thereof include a polyethylene film (PE film), apolyethylenevinylalcohol film (EVA film), a “film made of copolymer ofpolyethylene and ethylenevinylalcohol (hereinafter, referred to as a(PE+EVA) copolymer film)”, a “body obtained by combining the PE film tothe (PE+EVA) copolymer film”, or a “film obtained by simultaneouslyextruding the (PE+EVA) copolymer and polyethylene (a film in which oneside is a PE film side and the other side is a (PE+EVA) copolymer filmside)”.

The PE film can be obtained at low cost and is superior in a surfacesmoothness. Further, the (PE+EVA) copolymer film has proper adhesivenessand fissility with respect to the photosensitive dry film resist. Byusing the protective film, it is possible to improve the smoothness whena three-layer sheet including three layers of a protection layer, aphotosensitive dry film resist (layer of photosensitive resincomposition), and a support film is winded into a roll shape.

<Print Wiring Board>

Next, the print wiring board produced by using the photosensitive dryfilm resist is described as follows. The photosensitive dry film resistis used to form an interlayer insulation layer of the print wiringboard.

The following describes a technique for producing the print wiring boardby forming the photosensitive dry film resist according to the presentinvention as an interlayer insulation layer. As to the print wiringboard, a copper foil in which a pattern circuit is formed (hereinafter,this copper foil is referred to as a CCL having a circuit) is explainedas an example. However, also in case of forming a multi-layered printwiring board, it is possible to form the interlayer insulation layer inthe same manner.

First, the protective film is exfoliated from the three-layer sheethaving the protective film, the photosensitive dry film resist, and thesupport film. In the following description, the two-layer sheet fromwhich the protective film has been exfoliated is referred to as a“photosensitive dry film resist having a support film”. Further, theflexible copper plate having a circuit is covered by the photosensitivedry film resist having a support film, and the photosensitive dry filmresist and the flexible copper plate are combined with each other bythermal compression so as to be positioned opposite to each other. Asthe thermal compression, a thermal press process, a lamination process(thermal lamination process), a thermal roll lamination process, or thelike are carried out, and the thermal compression is not particularlylimited.

In case of combining the photosensitive dry film resist to the flexiblecopper plate by means of the thermal lamination process or the thermalroll lamination process (hereinafter, both the processes are referred tomerely as a lamination process), a process temperature is not less thana lower limit temperature at which the lamination process can be carriedout (hereinafter, the lower limit temperature is referred to as athermal pressure executable temperature). Specifically, the processtemperature preferably ranges from 50° C. to 150° C., more preferablyfrom 60° C. to 120° C., still more preferably from 80° C. to 120° C.

When the process temperature exceeds 150° C., cross-linking reaction ofphotosensitive reaction groups contained in the photosensitive dry filmresist occurs at the time of the lamination process, so that thephotosensitive dry film resist is progressively cured. Thus, it is notpreferable that the process temperature exceeds 150° C. While, when theprocess temperature is less than 50° C., the fluidity of thephotosensitive dry film resist is low, so that it is difficult to mountthe pattern circuit. Further, the adhesiveness between thephotosensitive dry film resist and a copper circuit or a base film ofthe CCL having a circuit may drop.

Due to the thermal compression, the photosensitive dry film resist islaminated on the CCL having a circuit, and the support film islaminated, thereby obtaining a sample. Next, the pattern exposure andthe development are carried out with respect to the laminate sample. Incarrying out the pattern exposure and the development, a photomaskpattern is disposed on the support film of the laminate sample, and anexposure process is carried out through the photomask. Thereafter, thesupport film is exfoliated and the development process is carried out,thereby forming a hole (via) corresponding to the photomask pattern.

Note that, in the foregoing example, the support film is exfoliatedafter the exposure process, but the exfoliation may be carried out aftercombining the photosensitive dry film resist having a support film ontothe CC1 having a circuit, that is, the exfoliation may be carried outbefore the exposure process. However, in order to protect thephotosensitive dry film resist, it is preferable to carry out theexfoliation after the exposure process has been completed.

As a light source used in the exposure, it is preferable to use a lightsource which effectively emits light whose wavelength ranges from 300 to430 nm. This is because the photoreaction initiator contained in thephotosensitive dry film resist generally functions by absorbing lightwhose wavelength is 450 nm or less.

Further, as the developer used in the development process, a basicsolution in which a basic compound has been dissolved is used. As asolvent which dissolves the basic compound, any solvent may be used aslong as the solvent can dissolve the basic compound. In terms of anenvironmental problem, it is preferable to use water.

Examples of the basic compound include: hydroxide or carbonate ofalkaline metal or alkaline earth metal such as sodium hydroxide,potassium hydroxide, sodium carbonate, and sodium hydrogen carbonate;organic amine compound such as tetramethylammoniumhydroxide; and thelike. Specifically, it is possible to use compounds exemplified in<Developer> of Embodiment 1. As the basic compound, one kind may beused, or two or more kinds of compounds may be used.

A concentration of the basic compound contained in the basic solutionpreferably ranges from 0.1 to 10 wt %. In terms of an anti-alkaliproperty of the photosensitive dry film resist, the concentration morepreferably ranges from 0.1 to 5 wt %.

Note that, the development process is not particularly limited. However,for example, it is possible to adopt: a method in which a developingsample is placed into basic solution and the basic solution is stirred;a method in which the developer is sprayed to the developing sample; anda similar method.

In the present invention, particularly, it is preferable to use 1 wt %of sodium hydroxide whose temperature has been adjusted to 40° C. as thedeveloper so as to carry out the development with a spray developingdevice. The spray developing device is not particularly limited as longas the device sprays the developer to the sample.

Further, time taken to form a predetermined pattern on thephotosensitive dry film resist is not particularly limited, but thedeveloping time is preferably 180 seconds or less, more preferably 90seconds or less, most preferably 60 seconds or less. It is notpreferable that the developing time exceeds 180 seconds in terms of theproductivity.

Here, as a standard of the developing time, time taken to dissolve thephotosensitive dry film resist in the B stage (half-cured) state ismeasured. Specifically, an unexposed sample obtained by combining thephotosensitive dry film resist to a lustrous surface of the copper foilis subjected to the spraying development by using sodium hydroxideaqueous solution whose concentration is 1% (liquid temperature is 40°C.) as the developer at a spray pressure of 0.85MPa. It is preferablethat the spraying development causes the photosensitive dry film resistto be dissolved and removed in 180 seconds or less. When the time takento dissolve and remove the photosensitive dry film resist exceeds 180seconds, the workability drops.

As described above, after carrying out the exposure and developingprocesses, the heating cure is carried out with respect to thephotosensitive dry film resist. On this account, it is possible tocompletely cure the photosensitive dry film resist. As a result, thethus cured photosensitive dry film resist serves as an insulativeprotection film of the print wiring board.

Further, in case of forming a multi-layer print wiring board, aprotective layer of the print wiring is used as an interlayer insulationlayer, and sputtering or dipping is carried out with respect to theinterlayer insulation layer or a copper foil is combined to theinterlayer insulation layer, and then a pattern circuit is formedthereon, so as to laminate the photosensitive dry film resist asdescribed above. On this account, it is possible to produce themulti-layer print wiring board.

Note that, the present embodiment described the case where thephotosensitive dry film resist is used as the insulative protectionmaterial or the interlayer insulation material of the print wiringboard, but it is possible to use the photosensitive dry film resist forother purposes.

Embodiment 3

A photosensitive resin composition according to the present embodimentis a composition containing a soluble polyimide resin (K) having acarboxylic group and/or a hydroxyl group, a specific phenoxyphosphazenecompound (L), and (meth)acrylic compounds (M). The photosensitive resincomposition according to the present embodiment may further contain another component (N), if necessary. For example, the photosensitive resincomposition according to the present embodiment may further contain acompound, which gives a property such as adhesiveness, flame retardancy,heat resistance, anti-bending, and/or the like to a resultantphotosensitive dry film resist. A photosensitive dry film resistaccording to the present embodiment is prepared from the photosensitiveresin composition according to the present embodiment. In the following,each component is described.

<Soluble Polyimide Resin (K) having Carboxylic Group and/or HydroxylGroup>

The photosensitive resin composition according to the present embodimentcontains the soluble polyimide resin having a carboxyl group and/or ahydroxyl group. With this, the resultant photosensitive dry film resistattains heat resistance, anti-bending property, excellent mechanicalproperty, electric insulation property, and anti-chemical property.Further, the presence of the carboxylic group and/or hydroxyl group(preferably phenolic hydroxyl group) makes it possible to develop watersystem.

The soluble polyimide resin (K) may be the soluble polyimide resin (G-1)described in Embodiment 2. That is, it is preferable that the solublepolyimide resin (K) have a carbon-carbon double bond, for example, in aside chain thereof. Moreover, the soluble polyimide resin (K) may besimilar to the soluble polyimide resin (G-1) in terms of solubility withrespect to an organic solvent, weight-average molecular weight, acidicequivalent, and the like. The organic solvent used in Embodiment 2 maybe adopted in the present embodiment.

<Production Method of the Soluble Polyimide Resin (K)>

For explaining a production method of the soluble polyimide resin havinga carboxylic group and/or a hydroxyl group, a synthesis method of apolyamide acid, and a method for imidizing the polyamide acid bydehydration ring closure are described below.

<Synthesis Method of Polyamide Acid>

The synthesis methods described in Embodiments 1 and 2 may be adoptedhere. That is, the soluble polyimide resin (K) may be prepared from apolyamide acid, which is a precursor thereof. The polyamide acid may beprepared by reacting a diamine with an acid dianhydride in an organicsolvent. More specifically, a diamine solution is prepared by dissolvingthe diamine in the organic solvent under inert atmosphere using argon,nitrogen, or the like, or by prepare a slurry of the diamine bydiffusing the diamine in the organic solvent under inert atmosphereusing argon, nitrogen, or the like. The acid dianhydride may be addedinto the diamine solution by adding (i) a solution in which the aciddianhydride is dissolved in the organic solvent, (ii) a slurry of theacid dianhydride diffused in the organic solvent, or (iii) the aciddianhydride in a solid form. The compound and the acid dianhydride maybe the diamine and the acid anhydride used in the production of thesoluble polyimide (G-1) in Embodiment 2.

In the present embodiment, temperature condition of the reaction of thediamine with the acid dianhydride (i.e., the synthesis reaction of thepolyamide acid) is not particularly limited, but is preferably 80° C. orless, and more preferably in a range of 0° C. to 50° C. At a temperatureabove 80° C., there is a risk of causing decomposition of the polyamideacid. On the other hand, polymerization reaction may be slow at atemperature of 0° C. or below. Moreover, reaction time may be setarbitrarily within a range of 10 minutes to 30 hours.

Further, the organic solvent for use in the synthesis reaction of thepolyamide acid is not particularly limited as long as the solvent is anorganic polar solvent. Examples of the organic solvent include: theorganic solvents listed in Embodiment 2; ethers solvents such astetrahydrofuran, dioxane, dioxolane, and the like; and the like organicsolvent.

<Imidization of Polyamide Acid>

Imidization of the polyamide acid may be carried out by the same methodas in Embodiment 2. Moreover, the imidization may be attained bydehydration ring closure of the polyamide acid carried out by thermallydehydrating the polyamide acid under reduced pressure in a containerwhich has been subjected to mold-releasing treatment such as coatingwith fluorine resin.

<Polyimide having at Least One Kind of Carbon-carbon Double Bond, whichis Selected from an Acryl Group, a Methacryl Group, a Vinyl Group, andan Allyl Group>

Next, the thus obtained soluble polyimide resin (K) is denaturalizedthereby to introduce therein a photosensitive group such as an acrylgroup, a methacryl group, a vinyl group, an allyl group, and/or thelike.

It is preferable that the soluble polyimide according to the presentembodiment having the carboxyl group and/or hydroxyl group be thedouble-bond polyimide resin. More specifically, it is more preferablethat the soluble polyimide have, for example, in its side chain, atleast one kind of carbon-carbon double bond, which is selected from anacryl group, a methacryl group, a vinyl group, and an allyl group, eventhough the soluble polyimide may have a functional group having acarbon-carbon double bond except the functional groups mentioned above.

The double-bond polyimide resin according to the present embodiment maybe obtained by denaturalizing the soluble polyimide resin having thecarboxyl group and/or hydroxyl group by reacting it with a compoundhaving a carbon-carbon double bond. The denaturalizing may be carriedout in the same manner as in Embodiment 2 in terms of the compound to bereacted with the soluble polyimide resin, a solvent for use in thereaction, reaction conditions, and the like.

<Phenoxyphosphazene Compound (L)>

Next, the phenoxyphosphazene compound (L) is explained. Thephenoxyphosphazene compound (L) according to the present embodimentcomprises at least one of a circular phenoxyphosphazene compound (L-1)and a chain phenoxyphosphazene compound (L-2), and further comprises across-linked phenoxyphosphazene compound (L-3) which has a cross-linkedstructure in which a cross-linking agent is introduced between oxygenatoms obtained by desorbing phenyl groups, the circularphenoxyphosphazene compound (L-1) being represented by formula (22)

where a represents an integer ranging from 3 to 30,

the chain phenoxyphosphazene compound (L-2) being represented by formula(23)

where R²⁵ represents group —N═(OPh)₃ or group —N═P(O)OPh, R²⁶ isgroup-P(OPh)4 or group-P(O)(OPh)₂, and b represents an integer rangingfrom 3 to 10000), and the cross-linking agent containing any one ofo-phenylene group, m-phenylene group, p-phenylene, group, orbisphenylene group represented by the following formula (3)

where R⁷ represents —C(CH₃)₂—, —SO₂—, —S—, or —O—, and p is 0 or 1).Furthermore, a phenyl-group containing ratio of the cross-linkedphenoxyphosphazene compound (L-3) is preferably in a range of 50% to99.9% with respect to a total of phenyl groups present in thephosphazene compound including at least one of the circularphenoxyphosphazene compound (L-1) and the chain phenoxyphosphazenecompound (L-2). The phenyl-group containing ratio can be obtained froman elemental analysis value.

Compared with the conventional phosphorus compounds, thephenoxyphosphazene compound (L) is excellent in anti-hydrolysisproperty. Moreover, compared with propoxylated phosphazene compounds,the phenoxyphosphazene compound (L) is excellent in heat resistance andcan give flame retardancy to the resultant photosensitive dry filmresist without deteriorating its property such as adhesiveness and thelike. Especially, the use of the cross-linked phenoxyphosphazenecompound is more preferable. This is because the cross-linkedphenoxyphosphazene compound (L-3) has an excellent phase solubility withrespect to polyimide resins, so that it makes bleeding hard to occur,and further the cross-linked phenoxyphosphazene compound (L-3) has lowvolatility, which can inhibit dropping and the like when flamed. Thecross-linked phenoxyphosphazene compound (L-3) is not particularlylimited. Examples of the cross-linked phenoxyphosphazene compound (L-3)include SPB-100, SPE-100, SPS-100, and SPB-156 (made by Otsuka ChemicalsInc.). The phenoxyphosphazene compound (L) may contain aphenoxyphosphazene compound other than the cross-linkedphenoxyphosphazene compound (L-3), in addition to the cross-linkedphenoxyphosphazene compound (L-3). The other phenoxyphosphazene compoundmay be the circular phenoxyphosphazene compound (L-1), the chainphenoxyphosphazene compound (L-2), and the like. The phenoxyphosphazenecompound (L) is preferably used in an amount in a range of 1 to 100parts by weight, more preferably in a range of 1 to 50 parts by weight,and especially preferably in a range of 1 to 40 parts by weight, wherethe total of the soluble polyimide resin (K) and the later described(meth)acrylic compounds (M) is 100 parts by weight.

There is a possibility that the flame retardancy becomes insufficientwhen the amount of the phenoxyphosphazene compound (L) is less than 1part by weight where the total of the soluble polyimide resin (K) andthe later described (meth)acrylic compounds (M) is 100 parts by weight.On the other hand, if the amount of the phenoxyphosphazene compound (L)exceeded 100 parts by weight, the photosensitive dry film resist wouldpossibly becomes sticky in the B stage-state, the bleeding would be easyto occur during the thermo-pressing, and further, the cured productwould possibly have poor properties. Therefore, the amount of thephenoxyphosphazene compound (L) exceeded 100 parts by weight is notpreferable.

<(Meth)acrylic Compound (M)>

Next, the (meth)acrylic compounds (M) are described. The photosensitivecomposition comprising the (meth)acrylic compounds (M) can have goodcuring property. Further the photosensitive dry film resist producedtherefrom can be less viscoelastic during thermal process andexcellently flowable during thermal lamination process. That is, thephotosensitive composition comprising the (meth)acrylic compounds (M)makes it possible to perform thermal lamination process at a relativelylow temperature. This allows the composition to be used to bury anirregular surface of a circuit.

The (meth)acrylic compounds (M) according to the present embodiment maybe the (meth)acrylic compounds (I) used in Embodiment 2. Further, theconditions such as an amount of the (meth)acrylic compounds (M) to bemixed are preferably similar to those in Embodiment 2.

<Other Component (N)>

The photosensitive resin composition according to the present inventionmay comprise the other component (N) if necessary, in addition to thesoluble polyimide resin (K), phenoxyphosphazene compound (L), and(meth)acrylic compounds (M). The other component (N) may be, forexample, an epoxy resin, curing promotion agent and/or curing agent, aphotoreaction initiator and/or sensitizer, or the like.

<Epoxy Resin>

Use of the epoxy resin can give the thus produced photosensitive dryfilm resist a better adhesiveness with respect to a copper foil,polyimide film or the like.

The epoxy resin is not particularly limited and may be the same as theepoxy resin (J-1) used in Embodiment 2. Further, the conditions such asan amount of the epoxy resin to be mixed are preferably similar to thosein Embodiment 2.

<Curing Promotion Agent and/or Curing Agent>

In case where the epoxy resin is used as a material of thephotosensitive resin composition, a curing promotion agent and/or curingagent may be added to the photosensitive resin composition, so that thecuring of the produced photosensitive dry film resist can be moreefficient. There is no particular limitation in the curing promotionagent and/or curing agent. For example, the curing promotion agentand/or curing agent (J-2) used in Embodiment 2 may be adopted here.Further, the conditions such as an amount of the curing promotion agentand/or curing agent to be mixed are preferably similar to those inEmbodiment 2.

<Photoreaction Initiator/Sensitizer>

If a photoreaction initiator and/or sensitizer is added to thephotosensitive dry film resist, cross-linking reaction and/orpolymerization reaction may be promoted in that portion of thephotosensitive dry film resist which is exposed to light. With this, theexposed and unexposed portions of the photosensitive dry film resist canbe sufficiently different from each other in terms of solubility withrespect to an aqueous developer. As a result, it becomes possible tosuitably develop a pattern on the photosensitive dry film resist.

The photoreaction initiator and/or sensitizer (J-3) used in Embodiment 2may be adopted as the photoreaction initiator and/or sensitizer.Further, the conditions such as an amount of the photoreaction initiatorand/or sensitizer to be mixed are preferably similar to those inEmbodiment 2.

<Preparation Method of the Photosensitive Resin Composition andProduction Method of the Photosensitive Dry Film Resist>

In the following, the preparation method of the photosensitive resincomposition and production method of the photosensitive dry film resistare described. To produce the photosensitive dry film resist, an organicsolvent solution of the photosensitive resin composition is evenlyapplied and dried on a support film.

<Preparation Method of Photosensitive Resin Composition>

The preparation method of the photosensitive resin composition accordingto the present invention is explained below. The photosensitive resincomposition according to the present invention is a mixture of thesoluble polyimide (A), phenoxyphosphazene compound (L), (meth)acryliccompounds (C), and if necessary the other component (D), which are mixedin a given mixing ratio. The organic solvent solution of thephotosensitive resin composition is a solution in which thephotosensitive resin composition is dissolved in an organic solvent. Theorganic solvent is not particularly limited as long as it can dissolvethe components in the photosensitive resin composition. Examples of theorganic solvent include: ethers solvents such as dioxolane, dioxane,tetrahydrofuran, and the like; ketones solvents such as acetone,methylethylketones, and the like; alcohols solvents such as methanol,ethanol, and the like; and the like organic solvents. The organicsolvents may be used solely, or two or more of them may be used incombination. Because the organic solvent is removed in a later stage inthe manufacturing process, it is preferable for the sake of themanufacturing process to choose an organic solvent which can dissolvethe components in the photosensitive resin composition and which has aboiling point as low as possible.

<Production Method of the Photosensitive Dry Film Resist>

After that, the organic solvent solution of the photosensitive resincomposition is applied evenly on the support film, and then thermallytreated and/or blown with hot air. With this, the organic solvent isremoved and the photosensitive resin composition attains a film-likeform thereby forming the photosensitive dry film resist. The thusprepared photosensitive dry film resist, the photosensitive compositionis still in half-cured state (at the B stage) Therefore, thephotosensitive dry film resist can be appropriately flowable in thethermal compression process such as the thermal lamination process andthe like, and thus suitable for burying the pattern circuit of the printwiring board. Further, curing of the photosensitive dry film resist canbe completed by exposure process, thermal compression process, orthermal curing, after burying the pattern circuit therewith.

The production method of the photosensitive dry film resist may besimilar to those in Embodiment 2. Moreover, the present embodiment ispreferably similar to Embodiment 2 in terms of a material and thicknessof the supporting film, a material of a protective film, laminationconditions of the films, and the like conditions.

<Production of the Print Wiring Board>

Next, the print wiring board produced by using the photosensitive dryfilm resist is described below. The photosensitive dry film resist is,for example, used to form an interlayer insulation film of the printwiring board. For example, production of the print wiring boardaccording to the present embodiment may be carried out in a mannersimilar to that of Embodiment 2. That is, if a CCL on which a circuit ismounted is used, it is possible to produce the print wiring board bythermo compression and exposure/development process. In this case, thethermo compression and exposure/development process is preferablycarried out in a manner similar to that of Embodiment 2.

Note that, the photosensitive dry film resist according to the presentembodiment is applicable to usages other than using it as the insulativeprotection material or interlayer insulation material of the printwiring board, even though the use of the photosensitive resin as theinsulative protection material or interlayer insulation material isexemplified here again.

EXAMPLES

The present invention is described below referring to Examples andComparative Examples, which are not to limit the present invention. Fora person skilled in the art, it is possible to make various changes,modification, and alternation within the scope of the present invention.In Examples 10 to 26 and Comparative Examples 1 and 2, variousproperties of photosensitive resin compositions are measured andevaluated in the following manners.

[Flame Retardancy]

Flame retardancy test was carried out in the following manner accordingto retardancy test standard UL94 for plastic materials. A solution of aphotosensitive resin composition was applied on a polyimide film (madeby Kaneka Corp.: 25AH film) of 25 μm thickness by using a bar coaterwhile shielding the photosensitive resin composition from light. Then,the photosensitive resin composition was dried at 60° C. for 5 minutes,and at 90° C. for 5 minutes, whereby the thus applied photosensitiveresin composition attained a thickness of 25 μm after drying. Afterthat, the photosensitive resin composition is exposed to light of 400 nmwith a dose of only 600 mJ/cm² and then thermally cured for 2 hours inan oven that was set at 180° C.

A sample prepared in this way was cut thereby to prepare 20 samples of1.27 cm width×12.7 cm length×50 μm thickness (including the thickness ofthe polyimide film).

Ten out of 20 samples were treated with a temperature of 23° C. under50% relative humidity for 48 hours (condition (1)), and the remainingten samples were treated with a temperature of 70° C. for 168 hours(condition (2)) and then cooled for 4 hours in a desiccator withanhydrous calcium chloride.

Then, these samples were held vertically by clumping upper parts thereofand fired by holding flame of a burner close to lower parts thereof for10 seconds. Ten seconds later the flame of the burner was moved awayfrom the samples, Then, how long the flaming or burning of the samplestook to be extinguished was measured. The sample was regarded as beingproper if the samples of both the conditions ((1) and (2)) stoppedburning or flaming and were self-extinguished within 5 seconds onaverage (average of 10 samples) from the time the flame of the burnerwas moved away from the samples, and none of them stopped burning orflaming and were self-extinguished beyond 10 seconds from the time theflame of the burner was moved away from the samples.

[Development]

A solution of a photosensitive resin composition was applied on anelectrolysis copper foil (produced by MITSUI MINING & SMELTING Co.,LTD.: NDP-3 ½ oz) of 25 μm thickness by using a bar coater. Then, thephotosensitive resin composition was dried at 60° C. for 5 minutes, andthen at 90° C. for 5 minutes, whereby the thus applied photosensitiveresin composition attained a thickness of 25 μm after drying. In thisway a lamination made from the photosensitive resin composition wasprepared. After placing a mask pattern thereon, the photosensitive resincomposition was exposed to light of wavelength 400 nm with a dose ofonly 300 mJ/cm². The photosensitive resin composition was developed bysubjecting to an aqueous solution of potassium hydroxide of 1 wt %(liquid temperature 40° C.) for 1 minute, the aqueous solution havingbeen sprayed thereon using a spray developer at a spray pressure 0.85MPa. The photo mask pattern had a fine square hole of 100×100 μm. Thepattern thus formed by the development was then washed with distilledwater to remove the developer and dried. If the development of the finesquare hole of 100×100 μm was successful, the sample was regarded asbeing proper.

[Soldering Heat Resistance]

An electrolysis copper foil (produced by MITSUI MINING & SMELTING Co.,LTD.: NDP-3 ½ oz) was subjected to soft etching with an aqueous solutionof sulfuric acid of 10 wt % (soft etching is a step for removinganti-lusting agent from a surface of the copper foil). After washed withwater, the surface of the copper foil was washed with ethanol andacetone, and then dried. A solution of a photosensitive resincomposition was applied on the electrolysis copper foil by using a barcoater, and then dried at 60° C. for 5 minutes, and further at 90° C.for 5 minutes, whereby the thus applied photosensitive resin compositionattained a thickness of 25 μm after drying. After that, the thuslaminated photosensitive resin composition was exposed to light of 400nm wavelength with a dose of only 300 mJ/cm². Then, thus prepared samplewas cut into 4 cm square, and cured at 180° C. for 2 hours. The samplewas conditioned under normal condition (1) (20° C./relative humidity of40%/24hours) or under humid condition (2) (40° C./relative humidity of85%/48 hours). After that, the sample was dipped in a melted solder at atemperature of 270° C. or higher. It was observed as to whether or notswelling occurred in an interface between the copper foil and thecoverlay and whether or not the coverlay was exfoliated from the copperfoil. By dipping the sample in the melted solder for 30 seconds every10° C. temperature elevation while gradually increasing the temperatureof the melted solder, it was also observed until which temperature thesample had no such abnormality. A highest temperature at which no suchabnormality occurred was put as 30-second-dipable temperature.

[Anti Migration]

Only one side of a flexible copper laminate plate produced by NipponSteel Chemical Co., Ltd. (double-side copper lamination board formed byplacing copper foil layers on a polyimide resin) SC18-25-00 WE wassubjected to etching thereby removing the copper foil from the one side.In this way, a single-side flexible copper laminate plate was prepared.On the single-side flexible copper laminate plate an interleave patternas illustrated in FIG. 1 was formed. Lines/spaces of the interleavepattern were 40 μm and 40 μm. On the interleave pattern, aphotosensitive film from which a protection film had been exfoliated wasplaced and laminated applying a temperature of 100° C. and a pressure of20000 Pa·m. Then, the lamination was exposed to light of 400 nm with adose of only 1800m J/cm². After that, a cover film was laminated thereonby heating at 180° C. for 2 hours.

In an environmental testing machine adjusted to 85° C. and 85%RH, a DCvoltage of 100V was applied across the interleave pattern covered withthe photosensitive film. Variation of resistance and whether or notmigration occurred were observed for 1000 hours. An insulationresistance after 1000 hours and whether or not migration occurred in1000 hours were evaluated as test results. As to the insulationresistance, it was regarded as being proper if the insulation resistancewas at least 10⁶ Ω after 1000 hours.

[Adhesiveness]

The adhesiveness was measured in accordance with JIS-D-0202.

[Insulation Resistance]

The insulation resistance was measured in accordance with JIS-C-6481.

[Material to Use]

The following commercially available products were used as materialsglycidyl methacrylate (produced by Wako Pure Chemical Industries, Ltd.),NK-oligo EA-1010 (SHIN-NAKAMURA CHEMICAL CO., LTD.), triethyl amine(Wako Pure Chemical Industries, Ltd.), tetrahydrofuran (Wako PureChemical Industries, Ltd.), and hexane (Wako Pure Chemical Industries,Ltd.). NK-oligo EA-10101 has a structure represented by the followingformula (18):

An average molecular weight of NK-oligo EA-10101 is 448.

Further, NMR (Nuclear Magnetic Resonance Spectrum) used was Gemini madeby Varian. The measurement was carried out at 25° C.

Synthesis Example 1 Synthesis of Raw Material Phosphazene Compound

Into a 5 L-flask provided with a reflex condenser, thermometer, stirringdevice, a dropping device for dropping phosphorus trichloride, and atube for introducing chloride gas, 2.5 L of chlorobenzen, 182.5 g (3.4mol) of ammonium chloride, and 2.5 g of zinc chloride were introduced,thereby to obtain a mixture dispersion liquid. The dispersion liquid washeated to a temperature of 130° C. Under reflux, 425.5 g was droppedtherein for 48 minutes at a rate of 9 g/min, and concurrently 227 g ofchloride gas was supplied therein for 46 hours at a rate of 5 g/min.After the supply of phosphorous trichloride and chloride gas, the refluxwas further continued for 150 minutes (at 131° C.). Then, the reactionwas completed. Next, suction filtration was carried out to removeunreacted ammonium chloride. The filtrate was distilled under reducedpressure of 1.0 to 3.0 hPa at a temperature of 30° C. to 50° C., therebydistilling off chlorobenzene. In this way, a reaction product of 352 gwas obtained. Yield of the reaction product was 98.1% with respect tophosphorus trichloride, which was the reaction product.

The thus prepared reaction product was dissolved into chlorobenzeneagain and recrystallized, thereby obtaining a mixture ofhexachlorocyclotriphosphazene and octachlorocyclotetraphosphazene (226g: hexachlorocyclotriphosphazene: 76%, octachlorocyclotetraphosphazene:24%).

The chlorobenzene solution left over after the re crystallization wasconcentrated thereby obtaining 125 g of circular phosphazene compoundand chain phosphazene compound (a mixture of the phosphazene compoundsrepresented by the general formulae (4) and (5) where m and n are in arange of 3 to 15). Further, the mixture of hexachlorocyclotriphosphazeneand octachlorocyclotetraphosphazene was subjected to recrystallizationprocess with hexane three times, thereby obtaining 155 g ofhexachlorocyclotriphosphazene of 99.9% purity.

Synthesis Example 2 Synthesis of Phenoxyphosphazene Compound (A-1)

In a 2 L four-necked flask provided with a reflux condenser,thermometer, stirring device, and dropping funnel, 58 g ofhexachlorocyclotriphosphazene (0.5 unit mol, where NPC 12 is one unit),and 100 ml of tetrahydrofuran (THF) were introduced, thereby preparing asolution.

A THF solution of sodium salt of 4-methoxyphenol (149.0 g (1.2 mol) of4-methoxyphenol, 25.3 g (1.1 g-atom) of sodium and 600 ml of THF) wasprepared separately, and dropped into the thus prepared solution ofhexachlorocyclotriphosphazene. The dropping was carried out to take twohours. The drop reaction was carried out with cooling because thereaction was highly exothermic until approximately ⅓ amount of thesodium salt was added. When the remaining ⅔ amount of the sodium saltwas added, the reaction was not highly exothermic. However, the dropreaction was carried out with cooling to control reaction temperature ator below 30° C.

After the dropping, the reaction was continued with stirring at a roomtemperature for 12 hours. Next, to terminate the reaction, the reactionwas carried out for 6 hours refluxing the solvent. After the reaction,THF used as the solvent was distilled off under a reduced pressure.Then, the resultant was redissolved in 500 ml of toluene added thereto.After 500 ml of water was added thereto, an organic layer was separatedfrom the solution of the resultant and 500 ml toluene using a separatingfunnel. The organic layer was washed three times with an aqueoussolution of sodium hydroxide of 5 wt %, once with 500 ml of an aqueoussolution of (1+9) hydrochloric acid, once with 500 ml of sodium hydrogencarbonate solution of 5 wt %, and twice with 500 ml of water. Afterwashing, pH of a water layer was 7 to 8.

The organic layer was separated, and then dehydrated with magnesiumsulfuric anhydride. Then toluene was distilled off from the organiclayer, thereby obtaining 138.4 g ofhexa(4-methoxyphenoxy)cyclotriphosphazene in a yellowish solid form(yield 95%). Residual chlorine content was 0.02% and melting point was104° C. (literature value 103° C. to 104° C.).

Then, in a 2-L four-necked flask, and 130.6 g (0.45 unit mol) ofHexa(4-methoxyphenoxy)cyclotriphosphazene thus obtained and 1040 g (9mol) of pyridine chlorate were gradually heated and reacted with eachother at 205-210° C. for one hour. After cooled down to a roomtemperature, 300 ml of water was added therein to dissolve a reactionproduct and excess pyridine chlorate. Then, pH of the solution wasadjusted to pH 6 to 7 with sodium hydroxide of 20 wt %. In this way, areaction solution was prepared. Then, the reaction solution wassubjected to extraction four times with 500 ml ethyl acetate. Extractsof the four extractions were added together and then washed four timeswith 500 ml of saturated sodium sulfate solution. Then, an organic layerwas separated therefrom. The organic layer was dehydrated with magnesiumsulfuric anhydride, and then distilled under reduced pressure to distilloff ethyl acetate therefrom. Next, the concentrate was dissolved in 200ml of methanol. The methanol solution was added into 1.5 L of water.Crystallization was repeated three times. Thus obtained crystal wasdried under reduced pressure, thereby obtaining 94.8 g oflight-yellowing crystal (yield 80%).

A residual chlorine in the product was 0.01% or less. Hydroxide groupcontent (OH, %) was measured according to acetylation method usingacetic anhydride and pyridine (acetylation method is described inAnalytical Chemistry Manual (edited by Japan Society for AnalyticalChemistry), organic chemistry, p316). The hydroxide group content was12.9%. (Theoretical value is 12.9%, composition formula N₃P₃(OC₆H₄OH)₆,hydroxide group equivalent 131.8) Moreover, 1H- and ³¹P-NMR analysis ofthe product showed that the synthesis was successful.

Synthesis Example 3 Synthesis of Phenoxyphosphazene Compound (A-1)

A 4-methoxyphenoxy derivative was obtained according to the same methodas in Synthesis Example 2 except that 58 g (0.5 unit mol) of circularchlorophosphazene and chain chlorophosphazene were used. Yield was 135.7g (93%). Residual chloride content was 0.04%. A yellowish and highlyviscous material was obtained.

Methyl group was removed in the same manner as in Synthesis Example 2,except that 131.1 g (0.45 unit mol) of the thus obtained4-methoxyphenoxy derivative. This produced a product, which was lightbrown and highly viscous. Yield was 98.6 g (75%). Residual chloridecontent in the product was not more than 0.01%. 1H- and 31-NMR analysisof the product showed that the synthesis was successful. Hydroxide groupcontent was 12.7% (hydroxide group equivalent 133.9).

Synthesis Example 4 Synthesis of Phenoxyphosphazene Compound (A-1)

Into a 2 L four-necked flask provided with a reflux condenser,thermometer, stirring device, and dropping funnel, 58 g (0.5 unit molwhere NPC 12 is one unit) of hexachlorocyclotriphosphazene of 99.9%purity and 100 ml of THF were introduced, thereby to obtain a THFsolution. A THF solution of Na salt of 4-methoxyphenol was separatelyprepared by adding 68.3 g (0.55 mol) of 4-methoxyphenol, 11.1 g(0.44g-atom) of sodium, and 200 ml of THF). The THF solution of Na saltof 4-methoxyphenol was dropped into the THF solution ofhexachlorocyclotriphosphazene with stirring. The dropping was carriedout taking one hour to complete. Reaction was carried out withappropriate cooling not to allow reaction temperature to exceed 30° C.because the reaction was highly exothermic. After dropping, the reactionwas continued for 6 hours at 60° C. with stirring. A partiallysubstituted product obtained through this reaction had residual chloridecontent of 15.78% and its structure was deduced asN₃P₃Cl_(3.36)(OC₆H₄OCH₃)_(2.63).

A THF solution of sodium phenolate was separately prepared by adding61.2 g (0.65 mol) of phenol, 13.8 g (0.6 g-atom) of sodium, and 200 mlof THF. The THF solution of sodium phenolate was dropped therein withcooling not to allow reaction temperature to be more than 30° C. Thedropping was carried out to take one hour to complete. Then, thereaction was continued at a room temperature for 5 hours and then at areflux temperature for 3 hours. Then, the reaction was completed. Afterthe reaction, the THF serving as the solvent was distilled off underreduced pressure. Next, 500 ml of toluene was added to redissolve aproduct from the reaction. Then, 300 ml of water was further added, andwater-wash separation was performed. Thus obtained organic layer waswashed once with an aqueous solution of sodium hydroxide of 5 wt %, oncewith an aqueous solution of sodium hydroxide of 2 wt %, once with anaqueous solution of (1+9) chloride acid twice with water, once withsodium hydrogen carbonate of 5 wt %, and twice with water. Thereby, awater layer became neutral. Next, the organic layer was separated, anddehydrated with magnesium sulfuric anhydride. Then, toluene wasdistilled off therefrom. This produced 122.6 g (yield 95%) of product,which was light yellow and oily and had residual chloride content notmore than 0.01%.

Into a 2 L four-necked flask, 116.2 g (0.45 unit mol) ofcyclotriphosphazene in which 4-methoxyphenoxy group and phenoxy groupwere mixedly substituted, and 583.6 g (5.05 mol) of pyridine chloratewere introduced. They were gradually heated and reacted with each otherat 205-210° C. for one hour. Later process was carried out in the samemanner as in Synthesis Example 2, thereby obtaining 90.5 g of yellowsolid (yield 81.8%). The product had residual chloride content not morethan 0.01% and hydroxide content of 6.1% (theoretical value 6.1%,composition formula N₃P₃(OPh)_(3.36)(OC₆H₄OH)_(2.63), and hydroxidegroup equivalent 279).

Synthesis Example 5 Synthesis of Phenoxyphosphazene Compound (A-1)

Into a 2 L four-necked flask provided with a reflux condenser,thermometer, stirring device, and dropping funnel, 58 g (0.5 unit molwhere NPC 12 is one unit) of hexachlorocyclotriphosphazene of 99.9%purity and 100 ml of THF were introduced, thereby to obtain a THFsolution.

A THF solution of Na salt of 4-methoxyphenol was separately prepared byadding 37.2 g (0.3 mol) of 4-methoxyphenol, 6.0 g (0.26g-atom) ofsodium, and 200 ml of THF). The THF solution of Na salt of4-methoxyphenol was dropped into the THF solution ofhexachlorocyclotriphosphazene with stirring. The dropping was carriedout taking one hour to complete. Reaction was carried out withappropriate cooling not to allow reaction temperature to exceed 30° C.because the reaction was highly exothermic. After dropping, the reactionwas continued for 6 hours at 60° C. with stirring. A partiallysubstituted product obtained through this reaction had residual chloridecontent of 35.58% and its structure was deduced asN₃P₃Cl_(4.45)(OC₆H₄OCH₃)_(1.55).

A THF solution of sodium phenolate was separately prepared by adding79.1 g (0.85 mol) of phenol, 18.4 g (0.8 g-atom) of sodium, and 200 mlof THF. The THF solution of sodium phenolate was dropped the abovesolution with cooling not to allow reaction temperature to be more than30° C. The dropping was carried out to take one hour to complete. Then,the reaction was continued at a room temperature for 5 hours and then ata reflux temperature for 3 hours. After that, the reaction wascompleted. After the reaction, the THF serving as the solvent wasdistilled off under reduced pressure. Next, 500 ml of toluene was addedto redissolve a product from the reaction. Then, 300 ml of water wasfurther added, and water-wash separation was performed. Thus obtainedorganic layer was washed once with an aqueous solution of sodiumhydroxide of 5 wt %, once with an aqueous solution of sodium hydroxideof 2 wt %, once with an aqueous solution of (1+9) chloride acid twicewith water, once with sodium hydrogen carbonate of 5 wt %, and twicewith water. Thereby, a water layer became neutral. Next, the organiclayer was separated, and dehydrated with magnesium sulfuric anhydride.Then, toluene was distilled off. This produced 110.0 g (yield 90%) ofproduct, which was light yellow and oily and had residual chloridecontent not more than 0.01%.

Into a 2 L four-necked flask, 98.7 g (0.40 unit mol) ofcyclotriphosphazene in which 4-methoxyphenoxy group and phenoxy groupwere mixedly substituted, and 583.6 g (5.05 mol) of pyridine chloratewere introduced. They were gradually heated and reacted with each otherat 205-210° C. for one hour. Later process was carried out in the samemanner as in Synthesis Example 2, thereby obtaining 75.0 g of yellowsolid (yield 78.3%). The product had residual chloride content not morethan 0.01% and hydroxide content of 4.0% (theoretical value 4.0%,composition formula N₃P₃(OPh)_(4.45)(OC₆H₄OH)_(1.55), and hydroxidegroup equivalent 430).

Synthesis Example 6 Synthesis of Cross-linked PhenoxyphosphazeneCompound (A-2)

Into a 2 L four-necked flask provided with a reflux condenser,thermometer, stirring device, and dropping funnel, 58 g (0.5 unit molwhere NPC 12 is one unit) of hexachlorocyclotriphosphazene of 99.9%purity and 100 ml of THF were introduced, thereby to obtain a THFsolution.

A THF solution of Na salt of a phenol was separately prepared by adding37.2 g (0.3 mol) of 4-methoxyphenol, 11.0 g (0.10 mol) of resorcinol,12.6 g (0.55 g-atom) of sodium, and 400 ml of THF). The THF solution ofNa salt of the phenol was dropped into the THF solution ofhexachlorocyclotriphosphazene with stirring. The dropping was carriedout taking one hour to complete. Reaction was carried out withappropriate cooling not to allow reaction temperature to exceed 30° C.because the reaction was exothermic. After dropping, the reaction wascontinued for 6 hours at 60° C. with stirring. A partially substitutedproduct obtained through this reaction had residual chloride content of21.17% and its structure was deduced asN₃P₃Cl_(3.15)(OC₆H₄OCH₃)_(1.78).(OC₆H₄O)_(0.50)(OC₆H₄OH)_(0.07)).

A THF solution of sodium phenolate was separately prepared by adding79.1 g (0.85 mol) of phenol, 18.4 g (0.8 mol) of sodium, and 200 ml ofTHF. The THF solution of sodium phenolate was dropped the above solutionwith cooling not to allow reaction temperature to be more than 30° C.The dropping was carried out to take one hour to complete. Then, thereaction was continued at a room temperature for 5 hours and then at areflux temperature for 3 hours. Then, the reaction was completed. Afterthe reaction, the THF serving as the solvent was distilled off underreduced pressure. Next, 500 ml of toluene was added to redissolve aproduct from the reaction. Then, 300 ml of water was further added, andwater-wash separation was performed. Thus obtained organic layer waswashed once with an aqueous solution of sodium hydroxide of 5 wt %, oncewith an aqueous solution of sodium hydroxide of 2 wt %, once with anaqueous solution of (1+9) chloride acid twice with water, once withsodium hydrogen carbonate of 5 wt %, and twice with water. Thereby, awater layer became neutral. Next, the organic layer was separated, anddehydrated with magnesium sulfuric anhydride. Then, toluene wasdistilled off therefrom. This produced 110.0 g (yield 90%) of product,which was light yellow and oily and had residual chloride content notmore than 0.01%.

Into a 2 L four-necked flask, cyclotriphosphazene in which4-methoxyphenoxy group and phenoxy group were mixedly substituted, and583.6 g (5.05 mol) of pyridine chlorate were introduced. They weregradually heated and reacted at 205-210° C. for one hour. Later processwas carried out in the same manner as in Synthesis Example 2, therebyobtaining 104.9 g of yellow solid (yield 92%). The product had residualchloride content not more than 0.01% and hydroxide content of 4.6%(theoretical value 4.5%; composition(N₃P₃(OC₆H₅)_(3.15)(OC₆H₄OH)_(1.85)(OC₆H₄O)_(0.50)); hydroxide groupequivalent 370; a content ratio of phenyl group and hydroxyphenyl groupwas[{(OC₆H₅)_(3.15)+(OC₆H₄OH)_(1.85)}×100]/{(OC₆H₅)_(4.15)+(OC₆H₄OH)_(1.85)}=(5×100)/6=83.3%)),where the structure of the phenoxyphosphazene compound beforecrosslinking is put as {(OC₆H₅)_(4.15)+(OC₆H₄OH)_(1.85)}, for example.)TG/DTA analysis (thermogravimetric analysis) of the cross-linkedphenoxyphosphazene compound showed that its decomposition point was 322°C. and 5% weight reduction temperature was 332° C.

Example 1 An Example of Synthesis of Double-bond Phosphazene Compound

Into a three-necked flask provided with a reflux tube, 23.4 g (including84.0 mmol of hydroxide group) of the phenoxyphosphazene compoundsynthesized in Synthesis Example 4, and 40.0 g of tetrahydrofuran wereintroduced, the phenoxyphosphazene compound having hydroxide group withhydroxide group equivalent 279. Then, they were completely dissolved.13.1 g (92.4 mmol) of glycidyl methacrylate, 0.4 g (4.2 mmol) oftriethylamine were further added therein under nitrogen atmosphere withstirring. Thus prepared reaction solution was heated to 70° C. andstirred for 8 hours. After being concentrated, the reaction solution wasintroduced into hexane and then decanted, thereby to separate a producttherefrom (in this way, unreacted glycidyl methacrylate was removed).The product was dried under vacuum for one night. This produced 27.9 gof a phosphazene compound having an unsaturated double bond(methacryloyl group). The phosphazene compound was light brown andhighly viscous material. The product was measured as to 1 H-NMRspectrum, and integration values of two signals (5.7 and 6.0 ppm) ofalkene derived from methacryloyl group and of a signal (6.6-7.2 ppm) ofan aromatic compound derived from the phosphazene compound werecompared. From this, it was confirmed that reaction ratio (addition ofmethacryloyl group to hydroxide group of the phenoxyphosphazenecompound) was approximately 50%.

Example 2 An Example of Synthesis of Double-bond Phosphazene Compound

Into a three-necked flask provided with a reflux tube, 23.4 g (including84.0 mmol of hydroxide group) of the phenoxyphosphazene compoundsynthesized in Synthesis Example 4, and 40.0 g of tetrahydrofuran wereintroduced, the phenoxyphosphazene compound having hydroxide group withhydroxide group equivalent 279. Then, they were completely dissolved.35.8 g (252.0 mmol) of glycidyl methacrylate, 0.4 g (4.2 mmol) oftriethylamine were further added therein under nitrogen atmosphere withstirring. Thus prepared reaction solution was heated to 70° C. andstirred for 8 hours. After being concentrated, the reaction solution wasintroduced into hexane and then decanted, thereby to separate a producttherefrom. The product was dried under vacuum for one night. Thisproduced 33.9 g of a phosphazene compound having an unsaturated doublebond (methacryloyl group). The phosphazene compound was light brown andhighly viscous material.

Reaction ratio was measured in the same manner as in Example 1. Thereaction ratio was approximately 100%.

Example 3 An Example of Synthesis of Double-bond Phosphazene Compound

Into a three-necked flask provided with a reflux tube, 36.12 g(including 84.0 mmol of hydroxide group) of the phenoxyphosphazenecompound synthesized in Synthesis Example 5, and 75.0 g oftetrahydrofuran were introduced, the phenoxyphosphazene compound havinghydroxide group with hydroxide group equivalent 430. Then, they werecompletely dissolved. 35.8 g (252.0 mmol) of glycidyl methacrylate, 0.4g (4.2 mmol) of triethylamine were further added therein under nitrogenatmosphere with stirring. Thus prepared reaction solution was heated to70° C. and stirred for 8 hours. After being concentrated, the reactionsolution was introduced into hexane and then decanted, thereby toseparate a product therefrom. The product was dried under vacuum for onenight. This produced 44.1 g of a phosphazene compound having anunsaturated double bond (methacryloyl group). The phosphazene compoundwas light brown and highly viscous material.

Reaction ratio was measured in the same manner as in Example 1. Thereaction ratio was approximately 80%.

Example 4 An Example of Synthesis of Double-bond Phosphazene Compound

Into a three-necked flask provided with a reflux tube, 23.4 g (including84.0 mmol of hydroxide group) of the phenoxyphosphazene compoundsynthesized in Synthesis Example 4, and 40.0 g of tetrahydrofuran wereintroduced, the phenoxyphosphazene compound having hydroxide group withhydroxide group equivalent 297. Then, they were completely dissolved.18.8 g (42.0 mmol) of EA-1010, 0.4 g (4.2 mmol) of triethylamine werefurther added therein under nitrogen atmosphere with stirring. Thusprepared reaction solution was heated to 70° C. and stirred for 8 hours.After being concentrated, the reaction solution was introduced intohexane and then decanted, thereby to separate a product therefrom. Theproduct was dried under vacuum for one night. This produced 40.1 g of aphosphazene compound having an unsaturated double bond (acryloyl group).The phosphazene compound was light brown and highly viscous material.The product was measured as to 1 H-NMR spectrum, and integration valuesof signals (6.0, 6.3, and 6.6 ppm) derived from methacryloyl group andof a signal (7.3 ppm) of derived from phenoxy of the phosphazenecompound were compared. From this, it was confirmed that reaction ratio(addition of methacryloyl group to hydroxide group of thephenoxyphosphazene compound) was approximately 50%.

Example 5 An Example of Synthesis of Double-bond Phosphazene Compound

Into a three-necked flask provided with a reflux tube, 23.4 g (including84.0 mmol of hydroxide group) of the phenoxyphosphazene compoundsynthesized in Synthesis Example 4, and 40.0 g of tetrahydrofuran wereintroduced, the phenoxyphosphazene compound having hydroxide group withhydroxide group equivalent 297. Then, they were completely dissolved.37.6 g (84.0 mmol) of EA-1010, 0.4 g (4.2 mmol) of triethylamine werefurther added therein under nitrogen atmosphere with stirring. Thusprepared reaction solution was heated to 70° C. and stirred for 8 hours.After being concentrated, the reaction solution was introduced intohexane and then decanted, thereby to separate a product therefrom. Theproduct was dried under vacuum for one night. This produced 58.2 g of aphosphazene compound having an unsaturated double bond (acryloyl group).The phosphazene compound was light brown and highly viscous material.

Reaction ratio was measured in the same manner as in Example 4. Thereaction ratio was approximately 100%.

Example 6 An Example of Synthesis of Double-bond Phosphazene Compound

Into a three-necked flask provided with a reflux tube, 36.12 g(including 84.0 mmol of hydroxide group) of the phenoxyphosphazenecompound synthesized in Synthesis Example 5, and 75.0 g oftetrahydrofuran were introduced, the phenoxyphosphazene compound havinghydroxide group with hydroxide group equivalent 430. Then, they werecompletely dissolved. 37.6 g (84.0 mmol) of EA-1010, 0.4 g (4.2 mmol) oftriethylamine were further added therein under nitrogen atmosphere withstirring. Thus prepared reaction solution was heated to 70° C. andstirred for 8 hours. After being concentrated, the reaction solution wasintroduced into hexane and then decanted, thereby to separate a producttherefrom. The product was dried under vacuum for one night. Thisproduced 67.7 g of a phosphazene compound having an unsaturated doublebond (acryloyl group). The phosphazene compound was light brown andhighly viscous material.

Reaction ratio was measured in the same manner as in Example 4. Thereaction ratio was approximately 100%.

Example 7 An Example of Synthesis of Double-bond Phosphazene Compound

Into a three-necked flask provided with a reflux tube, 19.77 g(including 150 mmol of hydroxide group) of the phenoxyphosphazenecompound synthesized in Synthesis Example 2, 14.2 g (100 mmol) ofglycidyl methacrylate, and 0.4 g (4.2 mmol) of triethylamine were addedunder nitrogen atmosphere with stirring, the phenoxyphosphazene compoundhaving hydroxide group with 131.8 hydroxide equivalent. Thus preparedreaction solution was heated to 70° C. and stirred for 8 hours. Thereaction solution was introduced into hexane and then decanted, therebyto separate a product therefrom. The product was dried under vacuum forone night. This produced 27.0 g of a phosphazene compound having anunsaturated double bond (methacryloyl group). The phosphazene compoundwas light brown and highly viscous material.

Reaction ratio was measured in the same manner as in Example 1. Thereaction ratio was approximately 60%.

Example 8 An Example of Synthesis of Double-bond Phosphazene Compound

Into a three-necked flask provided with a reflux tube, 20.1 g (including150 mmol of hydroxide group) of the phenoxyphosphazene compoundsynthesized in Synthesis Example 3, 14.2 g (100 ml) of glycidylmethacrylate, and 0.4 g (4.2 mmol) of triethylamine were added undernitrogen atmosphere with stirring, the phenoxyphosphazene compoundhaving hydroxide group with 133.9 hydroxide equivalent. Thus preparedreaction solution was heated to 70° C. and stirred for 8 hours. Thereaction solution was introduced into hexane and then decanted, therebyto separate a product therefrom. The product was dried under vacuum forone night. This produced 27 g of a phosphazene compound having anunsaturated double bond (methacryloyl group). The phosphazene compoundwas light brown and highly viscous material.

Reaction ratio was measured in the same manner as in Example 1. Thereaction ratio was approximately 55%.

Example 9 An Example of Synthesis of Double-bond Phosphazene Compound

Into a three-necked flask provided with a reflux tube, 37 g (including100 mmol of hydroxide group) of the phenoxyphosphazene compoundsynthesized in Synthesis Example 6, 9.94 g (70 mmol) of glycidylmethacrylate, and 0.4 g (4.2 mmol) of triethylamine were added undernitrogen atmosphere with stirring, the phenoxyphosphazene compoundhaving hydroxide group with 370 hydroxide equivalent. Thus preparedreaction solution was heated to 70° C. and stirred for 8 hours. Afterbeing concentrated, the reaction solution was introduced into hexane andthen decanted, thereby to separate a product therefrom. The product wasdried under vacuum for one night. This produced 41.0 g of a phosphazenecompound having an unsaturated double bond (methacryloyl group). Thephosphazene compound was light brown and highly viscous material.

Reaction ratio was measured in the same manner as in Example 1. Thereaction ratio was approximately 60%.

Example 10

The following components (a) to (d) were added together, and thoroughlymixed by using a three-arm roll mil, thereby to obtain a photosensitiveresin composition.

(a) the double-bond phosphazene compound synthesized in Example 1: 100parts by weight

(b) Photoreaction initiator

bis(2,4,6-trimethylbenzoyl)phenylphosphinoxide (Ciba SpecialtyChemicals): 2 parts by weight

(c) Other

Epoxyacrylate resin (novolaks: commercial name K-48C, acid value 63,solid content 60 wt %): 10 parts by weight

bisphenol A EO denatured (recurring unit of ethylene oxide denaturedportion; m+n≈4) diacrylate (TOAGOSEI CO., LTD. ): 10 parts by weight

bisphenol A diglycidylether acrylate additive (KYOEISHA CHEMICAL Co.,LTD): 10 parts by weight

4.4′ diaminodiphenylmethane: 1 part by weight

barium sulfate: 10 parts by weight

aluminum hydroxide: 10 parts by weight

The thus obtained photosensitive resin composition was evaluated invarious properties. The photosensitive resin composition was regarded asbeing proper in the flame retardancy test. In the soldering heatresistance test, the photosensitive resin component was regarded asbeing proper until 300° C. when treated with the normal condition anduntil 290° C when treated with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, 5×10⁸Ω was observed after 1000 hours, and noabnormality such as color change or the like was observed in the copperfoil. Thus, the photosensitive resin composition was regarded as beingproper in view of anti-migration property. Moreover, the photosensitiveresin composition was regarded as being proper in view of adhesiveness.Insulation resistance of the photosensitive resin composition was2×10¹³Ω.

Example 11

A photosensitive resin composition was prepared in the same manner as inExample 10, except that the double-bond phosphazene compound of Example10 was replaced with the double-bond phosphazene compound synthesized inExample 2.

The thus obtained photosensitive resin composition was evaluated in viewof various properties. The photosensitive resin composition was regardedas being proper in the flame retardancy test. In the soldering heatresistance test, the photosensitive resin component was regarded asbeing proper until 305° C. when treated with the normal condition anduntil 295° C. when treated with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, 7×10⁸Ω was observed after 1000 hours, and noabnormality such as color change or the like was observed in the copperfoil. Thus, the photosensitive resin composition was regarded as beingproper in view of anti-migration property. Moreover, the photosensitiveresin composition was regarded as being proper in view of adhesiveness.Insulation resistance of the photosensitive resin composition was3×10¹³Ω.

Example 12

A photosensitive resin composition was prepared in the same manner as inExample 10, except that the double-bond phosphazene compound of Example10 was replaced with the double-bond phosphazene compound synthesized inExample 3.

The thus obtained photosensitive resin composition was evaluated invarious properties. The photosensitive resin composition was regarded asbeing proper in the flame retardancy test. In the soldering heatresistance test, the photosensitive resin component was regarded asbeing proper until 290° C. when treated with the normal condition anduntil 285° C. when treated with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, 4×10⁸Ω was observed after 1000 hours, and noabnormality such as color change or the like was observed in the copperfoil. Thus, the photosensitive resin composition was regarded as beingproper in view of anti-migration property. Moreover, the photosensitiveresin composition was regarded as being proper in view of adhesiveness.Insulation resistance of the photosensitive resin composition was5×10¹³Ω.

Example 13

A photosensitive resin composition was prepared in the same manner as inExample 10, except that the double-bond phosphazene compound of Example10 was replaced with the double-bond phosphazene compound synthesized inExample 4.

The thus obtained photosensitive resin composition was evaluated invarious properties. The photosensitive resin composition was regarded asbeing proper in the flame retardancy test. In the soldering heatresistance test, the photosensitive resin component was regarded asbeing proper until 305° C. when treated with the normal condition anduntil 300° C. when treated with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, 8×10⁸Ω was observed after 1000 hours, and noabnormality such as color change or the like was observed in the copperfoil. Thus, the photosensitive resin composition was regarded as beingproper in view of anti-migration property. Moreover, the photosensitiveresin composition was regarded as being proper in view of adhesiveness.Insulation resistance of the photosensitive resin composition was2×10¹³Ω.

Example 14

A photosensitive resin composition was prepared in the same manner as inExample 10, except that the double-bond phosphazene compound of Example10 was replaced with the double-bond phosphazene compound synthesized inExample 5.

The thus obtained photosensitive resin composition was evaluated invarious properties. The photosensitive resin composition was regarded asbeing proper in the flame retardancy test. In the soldering heatresistance test, the photosensitive resin component was regarded asbeing proper until 310° C. when treated with the normal condition anduntil 300° C when treated with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, 7×10⁸Ωwas observed after 1000 hours, and noabnormality such as color change or the like was observed in the copperfoil. Thus, the photosensitive resin composition was regarded as beingproper in view of anti-migration property. Moreover, the photosensitiveresin composition was regarded as being proper in view of adhesiveness.Insulation resistance of the photosensitive resin composition was4×10¹³Ω.

Example 15

A photosensitive resin composition was prepared in the same manner as inExample 10, except that the double-bond phosphazene compound of Example10 was replaced with the double-bond phosphazene compound synthesized inExample 6.

The thus obtained photosensitive resin composition was evaluated invarious properties. The photosensitive resin composition was regarded asbeing proper in the flame retardancy test. In the soldering heatresistance test, the photosensitive resin component was regarded asbeing proper until 315° C. when treated with the normal condition anduntil 300° C. when treated with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, 7×10⁸Ω was observed after 1000 hours, and noabnormality such as color change or the like was observed in the copperfoil. Thus, the photosensitive resin composition was regarded as beingproper in view of anti-migration property. Moreover, the photosensitiveresin composition was regarded as being proper in view of adhesiveness.Insulation resistance of the photosensitive resin composition was6×10¹³Ω.

Example 16

A photosensitive resin composition was prepared in the same manner as inExample 10, except that the double-bond phosphazene compound of Example10 was replaced with the double-bond phosphazene compound synthesized inExample 7.

The thus obtained photosensitive resin composition was evaluated invarious properties. The photosensitive resin composition was regarded asbeing proper in the flame retardancy test. In the soldering heatresistance test, the photosensitive resin component was regarded asbeing proper until 305° C. when treated with the normal condition anduntil 295° C. when treated with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, 4×10⁸Ω was observed after 1000 hours, and noabnormality such as color change or the like was observed in the copperfoil. Thus, the photosensitive resin composition was regarded as beingproper in view of anti-migration property. Moreover, the photosensitiveresin composition was regarded as being proper in view of adhesiveness.Insulation resistance of the photosensitive resin composition was5×10¹³Ω.

Example 17

A photosensitive resin composition was prepared in the same manner as inExample 10, except that the double-bond phosphazene compound of Example10 was replaced with the double-bond phosphazene compound synthesized inExample 8.

The thus obtained photosensitive resin composition was evaluated invarious properties. The photosensitive resin composition was regarded asbeing proper in the flame retardancy test. In the soldering heatresistance test, the photosensitive resin component was regarded asbeing proper until 325° C. when treated with the normal condition anduntil 310° C. when treated with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, 1×10⁹Ω was observed after 1000 hours, and noabnormality such as color change or the like was observed in the copperfoil. Thus, the photosensitive resin composition got was regarded asbeing proper in view of anti-migration property. Moreover, thephotosensitive resin composition was regarded as being proper in view ofadhesiveness. Insulation resistance of the photosensitive resincomposition was 6×10¹³Ω.

Example 18

A photosensitive resin composition was prepared in the same manner as inExample 10, except that the double-bond phosphazene compound of Example10 was replaced with the double-bond phosphazene compound synthesized inExample 9.

The thus obtained photosensitive resin composition was evaluated invarious properties. The photosensitive resin composition was regarded asbeing proper in the flame retardancy test. In the soldering heatresistance test, the photosensitive resin component was regarded asbeing proper until 305° C. when treated with the normal condition anduntil 290° C. when treated with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, 6×10⁸Ω was observed after 1000 hours, and noabnormality such as color change or the like was observed in the copperfoil. Thus, the photosensitive resin composition was regarded as beingproper in view of anti-migration property. Moreover, the photosensitiveresin composition was regarded as being proper in view of adhesiveness.Insulation resistance of the photosensitive resin composition was5×10¹³Ω.

Comparative Example 1

A photosensitive resin composition was prepared in the same manner as inExample 10 except that the double-bond phosphazene compound of Example10 was omitted. The thus obtained photosensitive resin composition wasevaluated in various properties. The photosensitive resin compositionwas regarded as being improper in the flame retardancy test. In thesoldering heat resistance test, the photosensitive resin component wasregarded as being improper at 270° C. when treated either with thenormal condition or with the humid condition. Further, in thedevelopment test, the photosensitive resin composition was regarded asbeing proper because a square hole of 100 μm×100 μm was developed. As toanti-migration property, short-circuit occurred at 100 hours. Moreover,the photosensitive resin composition was regarded as being proper inview of adhesiveness. Insulation resistance of the photosensitive resincomposition was 2×10¹¹Ω.

Synthesis Example 7 Synthesis Example of Soluble Polyimide Resin (E)

Into a 500 ml separable flask provided with a stirring device, 17.3 g(0.030 mol) of2,2-bis(4-hydroxyphenyl)propanedibenzoate-3,3′,4,4′-tetracarboxylicdianhydride (ESDA) and 30 g of DMF were introduced, and stirred todissolve by using the stirring device. Next, 5.15 g (0.018 mol) of[bis(4-amino-3-carboxy)phenyl]methane (MBAA) made by Wakayama Seika Co.,Ltd. was dissolved in 9 g of dimethylformamide (DMF) and added in thecontent. Then, the content was stirred vigorously for one hour.

Further, 7.47 g (0.009 mol) of silicon diamine KF-8010 (commercial name:product of Shin-Etsu Silicone Co., Ltd.) was added therein. Then, theresultant was stirred for about one hour. Finally, 1.29 g (0.003 mol) ofdiamine made by Wakayama Seika Co., Ltd. (whose commercial name isBAPS-M, bis[4-(3-aminophenoxy)phenyl]sulfone). Then, the content wasvigorously stirred for one hour. In this way a polyamide solution wasobtained. The polyamide solution was transferred into a vat coated withTeflon (registered trademark) and dried in a vacuum oven under reducedpressure for 2 hours applying a temperature of 200° C and pressure of5000 Pa, thereby obtaining 26.40 g of a soluble polyimide resin.

Then, 15 g of the soluble polyimide resin thus synthesized was dissolvedin 50 g of dioxolane thereby to prepare a varnish, which had Sc (solidcontent) of 30%.

Synthesis Example 8 Synthesis Example of Soluble Polyimide Resin (E)

20.8 g (0.020 mol) of the soluble polyimide resin thus synthesized inSynthesis Example 7 was dissolved in 55 g of dioxolane. Then, 0.030 g ofQ1301 produced by Wako Pure Chemical Industries, Ltd. was added anddissolved therein warming the content by using an oil bath of 60° C.Then, 3.75 g (0.0264 mol) of glycidilymethacrylate was dissolved in 5 gof dioxolane and added into the solution thus prepared. Further, 0.01 gof triethylamine was added therein as a catalyst. Then, the solution wasstirred at 60° C. for 6 hours. Then, 22.4 g (0.05 mol) of NK-oligoEA-1010 (produced by SHIN-NAKAMURA CHEMICAL CO., LTD.) was addedtherein. Then, the solution was stirred at 60° C. for 6 hours. Thesolution was introduced and crushed in a beach blader in which 1 L ofmethanol had been purred and whose blade rotating at 11700 rpm. Resincontent precipitated was filtered out. The filtrate was extracted with aSoxhlet extractor using methanol as a solvent, and then dried, therebyobtaining 21 g of the soluble polyimide resin. The soluble polyimideresin was dissolved in dioxolane. In this way, a soluble polyimide resinadjusted to Sc (solid content) of 30%.

Synthesis Example 9 Synthesis Example of Soluble Polyimide Resin (E)

Into a 500 ml separable flask provided with a stirring device, 15.6 g(0.030 mol) of 4,4′-(4,4′-isopropyridinediphenoxy)bisphthalic anhydrideand 30 g of DMF were added and stirred to dissolve by using the stirringdevice. 6.58 g (0.023 mol) of diamine MBAA produced by Wakayama SeikaCo., Ltd. was dissolved in 9 g of DMF and added therein. Then, thesolution thus obtained was stirred for one hour. Further, 5.81 g (0.007mol) of silicondiamine KF-8010 (Shin-Etsu Silicone Co., Ltd.) was added.Then, the solution was stirred for about one hour. In this way, apolyamide solution was obtained. The polyamide solution was transferredinto a vat coated with Teflon (registered trademark) and dried in avacuum oven under reduced pressure for 2 hours applying a temperature of200° C. and pressure of 5000 Pa, thereby obtaining 26.0 g of a solublepolyimide resin.

17.94 g (0.020 mol) of the thus prepared soluble polyimide resin wasdissolved in 68.5 g of dioxolane. Then, 0.030 g of Q1301 produced byWako Pure Chemical Industries, Ltd. was added and dissolved thereinwarming the content by using an oil bath of 60° C. 11.4 g (0.030 mol) ofthe above-mentioned compound (Chemical 24) was dissolved in 5 g ofdioxolane and added into the prepared solution. Further, 0.01 g oftriethylamine was added therein as a catalyst. Then, the solution wasstirred at 60° C. for 6 hours. In this way, a soluble polyimide resinadjusted to Sc (solid content) of 30% was synthesized.

Synthesis Example 10 Synthesis Example of Soluble Polyimide Resin (E)

Into a 500 ml separable flask provided with a stirring device, 17.64 g(0.060 mol) of 2,3,3′,4′-biphenyltetracarboxylic anhydride and 50 g ofDMF were introduced, and stirred to dissolve by using the stirringdevice. Next, 12.87 g (0.045 mol) of diamine MBAA produced by WakayamaSeika Co., Ltd. was added therein. Then, the content was stirred for onehour vigorously. Further, 12.45 g (0.015 mol) of silicondiamine KF-8010(commercial name: produced by Shin-Etsu Silicone Co., Ltd.) was addedtherein. Then, the content was stirred about for one hour. In this way apolyamide solution was obtained. The polyamide solution was transferredinto a vat coated with Teflon (registered trademark) and dried in avacuum oven under reduced pressure for 2 hours applying a temperature of200° C. and pressure of 5000 Pa, thereby obtaining 39.0 g of a solublepolyimide resin.

27.2 g (0.040 mol) of the thus synthesized soluble polyimide resin wasdissolved in 83.3 g of dioxolane. Then, 0.030 g of Q1301 produced byWako Pure Chemical Industries, Ltd. was added therein and dissolvedwarming the content by using an oil bath of 60° C. Then, 8.95 g (0.063mol) of glycidilmethacrylate was dissolved in 5 g of dioxolane andadded in the solution. Further, 0.01 g of triethylamine was addedtherein as a catalyst. Then, the solution was stirred at 60° C. for 6hours. In this way, a soluble polyimide resin, which was denatured to Sc(solid content) of 30%, was synthesized.

Example 19

A photosensitive resin composition was prepared by mixing the followingcomponents (a) to (d) together. The photosensitive resin composition wasapplied on a PET film thereby to produce a photosensitive dry filmresist. The photosensitive dry film resist had a thickness ofapproximately 25 μm on the PET film and was in a half-cured state (Bstage state). On the photosensitive dry film resist with the PET film, aprotection film was laminated thereby to obtain a three-layer sheet.

(a) double-bond phosphazene compound synthesized in Example 1: 35 partsby weight (based on solid content by weight)

(b) soluble polyimide resin synthesized in Synthesis Example 7: 50 partsby weight

(c) A compound having a carbon-carbon double bond (monomer forcopolymerization)

bisphenol A to which diglycidylether acrylate was added (KYOEISHACHEMICAL Co., LTD: commercial name): 5 parts by weight

bisphenol A EO denatured (m+n≈2) diacrylate (TOAGOSEI CO., LTD.): 10parts by weight

(d) photoreaction initiator

3,3′,4′4-tetra(t-butylperoxycarbonyl)benzophenon: 1 part by weight

4,4′-diethylaminobenzophenone: 1 part by weight

Development property test of the photosensitive dry film resist showedthat a fine hole of 100 μm in diameter and a line of 100 μm/100 μm weredeveloped. Thus, the photosensitive dry film resist was regarded asbeing proper in the development property test. As to adhesive property,the photosensitive dry film resist was regarded as being proper becauseno exfoliation was observed. Further, the photosensitive dry film resistwas regarded as being proper in the flame retardancy test.

Soldering heat resistance: no abnormality such as swelling, exfoliation,or the like was observed after one-minute dipping at 270° C. either whentreaded with the normal condition or when treated with the humidcondition. Moreover, no abnormality was observed after 30-second dip at340° C. either when treated with the normal condition or when treatedwith the humid condition.

Anti-migration test: a resistance of 10⁸Ω or more was observed and noabnormality such as dendrite was observed after 1000 hours.

The insulation resistance was 2×10¹⁴Ω when treated with the normalcondition and 7×10¹³Ω when treated with the humid condition.

Example 20

A photosensitive resin composition was prepared by mixing the followingcomponents (a) to (d) together. The photosensitive resin composition wasapplied on a PET film thereby to produce a photosensitive dry filmresist. The photosensitive dry film resist had a thickness ofapproximately 25 μm on the PET film and was in a half-cured state (Bstage state). On the photosensitive dry film resist with the PET film, aprotection film was laminated thereby to obtain a three-layer sheet.

(a) double-bond phosphazene compound synthesized in Example 2: 35 partsby weight (based on solid content by weight)

(b) soluble polyimide resin synthesized in Synthesis Example 8: 50 partsby weight

(c) A compound having a carbon-carbon double bond (monomer forcopolymerization)

bisphenol A to which diglycidylether acrylate was added (KYOEISHACHEMICAL Co., LTD: commercial name): 5 parts by weight

bisphenol A EO denatured (m+n≈2) diacrylate (TOAGOSEI CO., LTD. ): 10parts by weight

(d) photoreaction initiator

3,3′,4′4-tetra(t-butylperoxycarbonyl)benzophenon: 1 part by weight

4,4′-diethylaminobenzophenone: 1 part by weight

Development property test of the photosensitive dry film resist showedthat a fine hole of 100 μm in diameter and a line of 100 μm/100 μm weredeveloped. Thus, the photosensitive dry film resist was regarded asbeing proper in the development property test. As to adhesive property,the photosensitive dry film resist was regarded as being proper becauseno exfoliation was observed. Further, the photosensitive dry film resistwas regarded as being proper in the flame retardancy test.

Soldering heat resistance: no abnormality such as swelling, exfoliation,or the like was observed after one-minute dipping at 270° C. either whentreated with the normal condition or when treated with the humidcondition. Moreover, no abnormality was observed after 30-second dip at350° C. either when treated with the normal condition or when treatedwith the humid condition.

Anti-migration test: a resistance of 10⁸Ω or more was observed and noabnormality such as dendrite was observed after 1000 hours.

The insulation resistance was 5×10¹⁴Ω when treated with the normalcondition and 8×10¹³Ω when treated with the humid condition.

Example 21

A photosensitive resin composition was prepared by mixing the followingcomponents (a) to (d) together. The photosensitive resin composition wasapplied on a PET film thereby to produce a photosensitive dry filmresist. The photosensitive dry film resist had a thickness ofapproximately 25 μm on the PET film and was in a half-cured state (Bstage state). On the photosensitive dry film resist with the PET film, aprotection film was laminated thereby to obtain a three-layer sheet.

(a) double-bond phosphazene compound synthesized in Example 3: 35 partsby weight (based on solid content by weight)

(b) soluble polyimide resin synthesized in Synthesis Example 9: 50 partsby weight

(c) A compound having a carbon-carbon double bond (monomer forcopolymerization)

bisphenol A EO denatured (m+n≈30) diacrylate (SHIN-NAKAMURA CHEMICALCO., LTD.: commercial name NK ester A-BPE-30): 5 parts by weight

bisphenol A EO denatured (m+n≈2) diacrylate (TOAGOSEI CO., LTD.): 10parts by weight

(d) photoreaction initiator

bis(2,4,6-trimethylbenzoil)-phenylphosphineoxide: 1 part by weight

Development property test of the photosensitive dry film resist showedthat a fine hole of 100 μm in diameter and a line of 100 μm/100 μm weredeveloped. Thus, the photosensitive dry film resist was regarded asbeing proper in the development property test. As to adhesive property,the photosensitive dry film resist was regarded as being proper becauseno exfoliation was observed. Further, the photosensitive dry film resistwas regarded as being proper in the flame retardancy test.

Soldering heat resistance: no abnormality such as swelling, exfoliation,or the like was observed after one-minute dipping at 270° C. either whentreated with the normal condition or when treated with the humidcondition. Moreover, no abnormality was observed after 30-second dip at360° C. either when treated with the normal condition or when treatedwith the humid condition.

Anti-migration test: a resistance of 10⁸Ω or more was observed and noabnormality such as dendrite was observed after 1000 hours.

The insulation resistance was 3×10¹⁴Ω when treated with the normalcondition and 6×10¹³Ω when treated with the humid condition.

Examples 22 to 25

Examples 22 to 25 were carried out in the same manner as Example 21except that the double-bond phosphazene compound (a) of Example 3 wasreplaced with the double-bond phosphazene compounds of Examples 4 to 7respectively.

In each of Examples 22 to 25, Development property test of thephotosensitive dry film resist showed that a fine hole of 100 μm indiameter and a line of 100 μm/100 μm were developed. Thus, thephotosensitive dry film resist was regarded as being proper in thedevelopment property test. As to adhesive property, the photosensitivedry film resist was regarded as being proper because no exfoliation wasobserved. Further, the photosensitive dry film resist was regarded asbeing proper in the flame retardancy test.

Soldering heat resistance: In each of Examples 22 to 25, no abnormalitysuch as swelling, exfoliation, or the like was observed after one-minutedipping at 270° C. either when treated with the normal condition or whentreated with the humid condition. Moreover, no abnormality was observedafter 30-second dip at 340° C. either when treated with the normalcondition or when treated with the humid condition.

Anti-migration test: a resistance of 10⁸Ω or more was observed and noabnormality such as dendrite was observed after 1000 hours.

The insulation resistance of Examples 22 to 25 were as follows: theinsulation resistance in Examples 22 was 1×10¹⁴Ω when treated with thenormal condition and 5×10¹³Ω when treated with the humid condition; theinsulation resistance in Examples 23 was 2×10¹⁴Ω when treated with thenormal condition and 6×10¹³Ω when treated with the humid condition; theinsulation resistance in Examples 24 was 4×10¹⁴Ω when treated with thenormal condition and 8×10¹³Ω when treated with the humid condition; andthe insulation resistance in Examples 25 was 3×10¹⁴Ω when treated withthe normal condition and 4×10¹³Ω when treated with the humid condition.

Example 26

A photosensitive resin composition was prepared by mixing the followingcomponents (a) to (d) together. The photosensitive resin composition wasapplied on a PET film thereby to produce a photosensitive dry filmresist. The photosensitive dry film resist had a thickness ofapproximately 25 μm on the PET film and was in a half-cured state (Bstage state). On the photosensitive dry film resist with the PET film, aprotection film was laminated thereby to obtain a three-layer sheet.

(a) double-bond phosphazene compound synthesized in Example 8: 20 partsby weight (based on solid content by weight)

double-bond phosphazene compound synthesized in Example 9: 15 parts byweight

(b) soluble polyimide resin synthesized in Synthesis Example 10: 50parts by weight

bisphenol A to which diglycidyl ether acrylate was added (KYOEISHACHEMICAL Co., LTD: commercial name): 15 parts by weight

(d) photoreaction initiator

bis(2,4,6-trimethylbenzoil)-phenylphosphineoxide: 1 part by weight

Development property test of the photosensitive dry film resist showedthat a fine hole of 100 μm in diameter and a line of 100 μm/100 μm weredeveloped. Thus, the photosensitive dry film resist was regarded asbeing proper in the development property test. As to adhesive property,the photosensitive dry film resist was regarded as being proper becauseno exfoliation was observed. Further, the photosensitive dry film resistwas regarded as being proper in the flame retardancy test.

Soldering heat resistance: no abnormality such as swelling, exfoliation,or the like was observed after one-minute dipping at 270° C. either whentreated with the normal condition or when treated with the humidcondition. Moreover, no abnormality was observed after 30-second dip at360° C. either when treated with the normal condition or when treatedwith the humid condition.

Anti-migration test: a resistance of 10⁸Ω or more was observed and noabnormality such as dendrite was observed after 1000 hours.

The insulation resistance was 5×10¹⁴Ω when treated with the normalcondition and 7×10¹³Ω when treated with the humid condition.

Comparative Example 2

A photosensitive resin composition was prepared by mixing the followingcomponents (a) to (d) together. The photosensitive resin composition wasapplied on a PET film thereby to produce a photosensitive dry filmresist. The photosensitive dry film resist had a thickness ofapproximately 25 μm on the PET film and was in a semi-cured state (Bstage state). On the photosensitive dry film resist with the PET film, aprotection film was laminated thereby to obtain a three-layer sheet.

(a) double-bond phosphazene compound: 0 part by weight (based on solidcontent by weight)

(b) soluble polyimide resin synthesized in Synthesis Example 7: 50 partsby weight

bisphenol A EO denatured (m+n≈30) diacrylate (SHIN-NAKAMURA CHEMICALCO., LTD.: commercial name NK ester A-BPE-30): 50 parts by weight

(d) photoreaction initiator

bis(2,4,6-trimethylbenzoil)-phenylphosphineoxide: 1 part by weight

Development property test of the photosensitive dry film resist showedthat a fine hole of 100 μm in diameter and a line of 100 μm/100 μm weredeveloped. Thus, the photosensitive dry film resist was regarded asbeing proper in the development property test. As to adhesive property,the photosensitive dry film resist was regarded as being proper becauseno exfoliation was observed. Further, the photosensitive dry film resistwas burned in the flame retardancy test, so it was regarded as beingimproper in the flame retardancy test.

Soldering heat resistance: no abnormality such as swelling, exfoliation,or the like was observed after one-minute dipping at 270° C. whentreated with the normal condition but swelling was observed afterone-minute dipping at 270° C. when treated with the humid condition.Moreover, no abnormality was observed after 30-second dip until 300° C.when treated with the normal condition but no abnormality was observedafter 30-second dip until 270° C. when treated with the humid condition.

Anti-migration test: short-circuit was observed at 300 hours. Dendritewas also observed at that point of time.

Insulation resistance was 2×10¹²Ω when treated with the normal conditionand 7×10¹⁰Ω when treated with the humid condition.

Further, as an example where the photosensitive resin composition isprepared in a manner different from the foregoing manner and an exampleof the photosensitive resin film obtained in this manner, the followingphotosensitive dry film resist was produced. A specific example of theproduction thereof is as follows. Further, the following shows a methodfor evaluating properties of organic solvent solutions andphotosensitive film resists of the photosensitive resin compositionsobtained in Examples 27 to 35 and Comparative Examples 3 to 8.

[Preparation 1 of Photosensitive Resin Composition]

The soluble polyimide resin (G-1) was dissolved in dioxolane, and itssolid content weight ratio %(Sc) was adjusted to 30%, thereby preparinga soluble polyimide resin (g-1) solution. With respect to the solution,the phenoxyphosphazene compound (H-1), the (meth)acrylic compounds (I),and if necessary other component (J) were mixed/stirred, therebypreparing an organic solvent solution of the photosensitive resincomposition so that its final solid content weight ratio %(Sc) was 30%.Here, the solid content weight ratio means a total weight of materialsother than the organic solvent, that is, a total weight of thecomponents (G-1), (H-1), (I), and (J). Even a liquid material wasregarded as the solid component.

[Production of Photosensitive Dry Film Resist]

The organic solvent solution of the photosensitive resin compositionobtained in [Preparation 1 of photosensitive resin composition] wasapplied to the support film so that thickness after being dried(thickness of the photosensitive dry film resist) ranged from 20 to 25μm. As the support film, a PET film (Lumirror (commercial name) producedby TORAY ADVANCED FILM Co., Ltd: its thickness was 25 μm) was used.Thereafter, the applied layer on the support film was dried at 100° C.for two minutes, thereby removing dioxolane. In this manner, a two-layersheet constituted of the photosensitive dry film resist/PET film(support film) was obtained. Note that, the photosensitive dry filmresist layer was in a half-cured state (B stage state).

Subsequently, a polyethylene film (GF-1 (commercial name) produced byTAMAPOLY Co., Ltd: its thickness was 40 μm) was roll-laminated on thephotosensitive dry film resist of the two-layer sheet at 20° C. and at anip pressure of 75000 Pa·m, thereby obtaining a three-layer sheet(laminate sample) having three layers (the protective film, thephotosensitive dry film resist, and the PET film).

[Flame Retardancy]

After exfoliating the protection film of the three-layer sheet of thephotosensitive dry film resist produced in the foregoing manner, thephotosensitive dry film resist was laminated on a polyimide film (25AHfilm produced by Kaneka Corp.) at 100° C. and at 75000 Pa·m. Next, theresultant was exposed to 600 mJ/cm² of light whose wavelength was 400nm, and the resultant was thermally cured in an oven of 180° C. for twohours.

Thus obtained sample was cut into a size of 1.27 cm (width)×12.7 cm(length)×50 μm (thickness) (including the thickness of the polyimidefilm). In this way, 20 samples were prepared. Among 20 samples, 10samples were processed (i) at 23° C. with 50% of relative humidity for48 hours, and other 10 samples were processed (ii) at 70° C. for 168hours, and then was cooled in a desiccator containing anhydrous calciumchloride for 4 or more hours.

An upper portion of each sample was clamped so as to be verticallyfixed, and a flame of a burner was positioned near to a lower portion ofthe sample for 10 seconds so that the lower portion caught fire. After10 seconds, the flame of the burner was separated away from the sample,and time (seconds) taken for the sample to be free from any flame orburning was measured. Under the foregoing condition (i) or (ii), whenthe sample became free from any frame or burning and realized selfextinction within 5 seconds (not more than 10 seconds) after separatingthe flame of the burner away from the sample, the photosensitive resincomposition or the photosensitive dry film resist was regarded as beingproper. When even a single sample failed in self extinction within 10seconds or when the flame rose to the clamp in the upper portion of thesample and the burning continued, the photosensitive resin compositionor the photosensitive dry film resist was regarded as being improper.

[Bleed]

The polyimide film/photosensitive dry film resist laminate produced inthe flame retardancy test was reserved in an environment whosetemperature was 85° C. and relative humidity was 85% for 100 hours. Thereserved sample was observed through an optical microscope at a scalingratio of 10000% so as to confirm whether there is any bleeding or not.

[Developing Property]

First, an electrolysis copper foil (NDP-3 ½ oz (commercial name)produced by MITSUI MINING & SMELTING Co., LTD.) whose thickness was 18μm was soft-etched with 10 wt % of a sulfuric aqueous solution for oneminute, and was rinsed with water. Thereafter, a surface of theresultant was rinsed with ethanol and acetone and was dried. Afterexfoliating the protective film of the photosensitive dry film resist,the resultant was laminated on a lustrous surface of the electrolysiscopper foil (having been soft-etched) at 100° C. and at 75000 Pa·m. Amask pattern having a minute square of 100×100 μm and a square of200×200 μm was placed on the PET film of the laminate, and the laminatewas exposed to 600 mJ/cm² of light whose wavelength was 400 nm.Thereafter, a spray developing device (ES-655D (commercial name) whichwas an etching machine produced by Sunhayato Corporation) was used todevelop the laminate in 1 wt % of potassium hydroxide aqueous solution(its temperature was 40° C.) at a spray pressure of 0.85 MPa with itsdeveloping time of 30 to 180 seconds. After being developed, thelaminate was rinsed with distilled water so as to remove the developer,and was dried. When at least a hole of 200×200 μm was found through theoptical microscope, the laminate was regarded as being proper.

[Heat Resistance (Soldering Heat Resistance)]

A copper foil (electrolysis copper foil produced by MITSUI MINING &SMELTING Co., LTD.) whose thickness was 35 μm was cut into 5×5 cm andwas subjected to soft etching with 10 wt % of sulfuric acid aqueoussolution for one minute, and was rinsed with water, and then the surfacewas rinsed with ethanol and acetone, and thus rinsed surface was dried.Subsequently, after exfoliating the protective film of thephotosensitive dry film resist cut into 4×4 cm, the resultant waslaminated on a lustrous surface of the electrolysis copper foil (havingbeen soft-etched) at 100° C. and at 75000 Pa·m. The photosensitive dryfilm resist of the combined sample was exposed to 300 mJ/cm² of lightwhose wavelength was 400 nm. Thereafter, the resultant was cured at 180°C. for two hours. The thus obtained sample was subjected to humidityconditioning under (i) a normal condition (at 20° C., with relativehumidity of 40%, for 24 hours) and (ii) a moisture absorption condition(at 40° C., with relative humidity of 85%, for 48 hours). Thereafter,the sample was dipped in melted solder, whose temperature was 270° C. orhigher, for 30 seconds. Then, whether or not swollenness occurred andwhether or not exfoliation occurred in an interface between the copperfoil and the photosensitive dry film resist were observed. Further, atemperature of the melted solder was gradually raised so as to check atemperature at which the sample was under an abnormal condition whiledipping the sample for 30 seconds per 10° C. A maximum temperature whichresulted no abnormal condition was defined as a 30-second-dipabletemperature. When the 30-second-dipable temperature was 300° C. orhigher, this sample was regarded as being proper.

[Materials Used]

As materials of the soluble polyimide resin (G-1), the followingcommercial products were used. The materials were(2,2′-bis(hydroxyphenyl)propanedibenzoate)-3,3′,4,4′-tetra carboxylatedianhydride (product of Wakayama Seika Co., Ltd.: hereinafter, referredto as ESDA), silicondiamine (KF-8010 (commercial name) produced byShin-Etsu Silicone Co., Ltd.), 2,2′-diaminobisphenol A (DAM-1(commercial name) produced by Gun Ei Chemical Industry Co., Ltd.), andbis [4-(3-aminophenoxy)phenyl]sulfone (hereinafter, referred to asBAPS-M).

Further, a weight-average molecular weight of the soluble polyimideresin (G-1) was measured with a high speed GPC (HLC-8220GPC (commercialname) produced by Tosoh Corporation), and was calculated with a sizeexclusion chromatography in accordance with conversion based onpolyethyleneoxide. Further, synthesis of the material phosphazenecompound, the phenoxyphosphagen compound, and the cross-linkedphenoxyphosphazene compound was carried out in the same manner as in theSynthesis Examples 1 to 6.

Synthesis Example 11 Synthesis Example of Soluble Polyimide Resin (G-1)

17.3 g (0.030 mol) of 2,2′-bis(hydroxyphenyl)propanedibenzoate-3,3′,4,4′-tetracarboxylate dianhydride (ESDA) and 30 g of dimethylformamide(DMF) were placed in a 500 ml separable flask provided with a stirrer,and the mixture was stirred, thereby dissolving the mixture. Next, 5.15g (0.018 mol) of [bis(4-amino-3-carboxy)phenyl]methane produced byWakayama Seika Co., Ltd. (MBAA) was. dissolved in 9 g of DMF, and themixture was stirred for one hour. After the solution became even, 7.47 g(0.009 mol) of silicondiamine (KF-8010 (commercial name) produced byShin-Etsu Silicone Co., Ltd.) was added thereto, and the mixture wasstirred for about one hour. Lastly, 1.29 g (0.003 mol) of diamine(bis[4-(3-aminophenoxy)phenyl]sulfone whose commercial name was BAPS-Mproduced by Wakayama Seika Co., Ltd.) was added thereto, and the mixturewas intensely stirred. The polyamide solution obtained in this mannerwas placed in a tray coated with fluorocarbon resin and was dried in avacuum oven at 200° C. under reduced pressure of 660 Pa for two hours,thereby obtaining 26.40 g of soluble polyimide resin having a carboxylgroup. In the soluble polyimide resin, an acid equivalent was 835 and aweight-average molecular weight was 37000.

Synthesis Example 12 Synthesis of Double-bond Polyimide Resin

20.0 g of (0.020 mol) of the soluble polyimide resin synthesized inSynthesis Example 11 was dissolved in 40 g of DMF. Further, 1.71 g(0.120 mol) of methacrylate glycidyl, 0.1 g (0.001 mol) oftriethylamine, and 0.02 g of N-nitrosphenylhydroxylaminealuminum saltserving as a polymerization inhibitor were added thereto, and themixture was stirred at 80° C. for 5 hours. The thus obtained solutionwas poured into 500 ml of methanole, and a deposited resin component wascrushed by a mixer, and the crushed resins were rinsed with methanol andwas dried, thereby obtaining 113.4 g of a double-bond polyimide resinhaving an unsaturated double bond (methacryloyl group). In thedouble-bond polyimide resin, an acid equivalent was 1811 and aweight-average molecular weight was 38000.

Synthesis Example 13 Synthesis of Soluble Polyimide Resin (A-1)

69.7 g (0.27 mol) of diamine DAM-1 (commercial name) produced by Gun EiChemical Industry Co., Ltd. and 100 g of DMF-1 (commercial name) wereplaced in a 500 ml separable flask provided with a stirrer, therebypreparing a DMF solution of DAM-1. Next, 24.9 g (0.03 mol) ofsilicondiamine (KF-8010 (commercial name) produced by Shin-Etsu SiliconeCo., Ltd.) was added thereto, and the mixture was intensely stirred.After the solution became even, a solution obtained by dissolving 173 g(0.30 mol) of ESDA in 300 g of DMF was added thereto, and the mixturewas intensely stirred for about one hour. The polyamide acid solutionobtained in this manner was placed in a tray coated with fluorocarbonresin and was dried in a vacuum oven at 200° C. under reduced pressureof 660 Pa for two hours, thereby obtaining 241.0 g of soluble polyimideresin having a hydroxyl group. In the soluble polyimide resin, an acidequivalent was 475 and a weight-average molecular weight was 26000.

Synthesis Example 12 Synthesis of Double-bond Polyimide Resin

100 g of the soluble polyimide resin synthesized in Synthesis Example 13was dissolved in 200 g of DMF. Further, 15.1 g (0.11 mol) ofmethacrylate glycidyl, 1.0 g (0.01 mol) of triethylamine, and 0.1 g ofN-nitrosphenylhydroxylaminealuminum salt serving as a polymerizationinhibitor were added thereto, and the mixture was stirred at 80° C. for5 hours. The thus obtained solution was poured into 500 ml of methanole,and a deposited resin component was crushed by a mixer, and the crushedresins were rinsed with methanol and was dried, thereby obtaining 113.4g of a double-bond polyimide resin having an unsaturated double bond(methacryloyl group). In the double-bond polyimide resin, an acidequivalent was 1132 and a weight-average molecular weight was 30000.

Example 27

15 g of the soluble polyimide resin synthesized in Synthesis Example 11was dissolved in 35 g of dioxolane, thereby preparing an organic solventsolution so that its solid content weight ratio (Sc) was 30%.

An organic solvent solution of the photosensitive resin composition wasprepared by mixing the following components so as to produce aphotosensitive dry film resist in a B stage state.

(a) Soluble Polyimide Resin

-   Soluble polyimide resin synthesized in Synthesis Example 11 (in    accordance with conversion based on a solid content): 40 parts by    weight    (b) Phenoxyphosphazene Compound-   Circular phenoxyphosphazene compound synthesized in Synthesis    Example 2: 25 parts by weight    (c) (Meth)acrylic Compound-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈4) diacrylate (ARONIX M-211B (commercial    name) produced by TOAGOSEI CO., LTD.): 5 parts by weight-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈30) diacrylate (NK ester A-BPE-30    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.): 20    parts by weight    (d) Other Component

Photoreaction initiator

-   Bis (2,4,6-trimethylbenzoyl)phenylphosphinoxide (IRGACURE 819    (commercial name) produced by Ciba Specialty Chemicals): 1 part by    weight

Epoxy Resin

-   Bisphenol A type epoxy resin (Epikote 828 (commercial name) produced    by Japan Epoxy Resins Co., Ltd.): 10 parts by weight

Curing Agent

-   4,4′-diaminodiphenylmethane (DDM): 1 part by weight

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows.

-   Flame retardancy test: The flame disappeared in 3.5 seconds on the    average, so that this was regarded as being proper.-   Bleed: There was no bleed.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 320° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

Example 28

15 g of the double-bond polyimide resin synthesized in Synthesis Example12 was dissolved in 35 g of dioxolane, thereby preparing an organicsolvent solution so that its solid content weight ratio (Sc) was 30%.

An organic solvent solution of the photosensitive resin composition wasprepared by mixing the following components so as to produce aphotosensitive dry film resist in a B stage state.

(a) Soluble Polyimide Resin

-   Double-bond polyimide resin synthesized in Synthesis Example 12 (in    accordance with conversion based on a solid content): 50 parts by    weight    (b) Phenoxyphosphazene Compound-   Circular phenoxyphosphazene compound and the chain    phenoxyphosphazene compound synthesized in Synthesis Example 3: 25    parts by weight    (c) (Meth)acrylic Compound-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈10) diacrylate (NK ester A-BPE-10    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.)): 10    parts by weight-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈30) diacrylate (NK ester A-BPE-30    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.): 15    parts by weight    (d) Other Component

Photoreaction initiator

-   Bis(2,4,6-trimethylbenzoyl)phenylphosphinoxide (IRGACURE 819    (commercial name) produced by Ciba Specialty Chemicals): 1 part by    weight

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows.

-   Flame retardancy test: The flame disappeared in 3.0 seconds on the    average, so that this was regarded as being proper.-   Bleed: There was no bleed.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 330° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

Example 29

15 g of the double-bond polyimide resin synthesized in Synthesis Example12 was dissolved in 35 g of dioxolane, thereby preparing an organicsolvent solution so that its solid content weight ratio (Sc) was 30%.

An organic solvent solution of the photosensitive resin composition wasprepared by mixing the following components so as to produce aphotosensitive dry film resist in a B stage state.

(a) Soluble Polyimide Resin

-   Double-bond polyimide resin synthesized in Synthesis Example 12 (in    accordance with conversion based on a solid content): 50 parts by    weight    (b) Phenoxyphosphazene Compound-   Circular phenoxyphosphazene compound synthesized in Synthesis    Example 4: 20 parts by weight    (c) (Meth)acrylic Compound-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n=4) diacrylate (ARONIX M-211B (commercial    name) produced by TOAGOSEI CO., LTD.): 5 parts by weight-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈30) diacrylate (NK ester A-BPE-30    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.): 15    parts by weight-   Epoxyacrylate (NK oligo EA-1010 (commercial name) produced by    SHIN-NAKAMURA CHEMICAL CO., LTD.): 10 parts by weight    (d) Other Component

Photoreaction Initiator

-   Bis (2,4,6-trimethylbenzoyl)phenylphosphinoxide (IRGACURE 819    (commercial name) produced by Ciba Specialty Chemicals): 1 part by    weight

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows.

-   Flame retardancy test: The flame disappeared in 3.0 seconds on the    average, so that this was regarded as being proper.-   Bleed: There was no bleed.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 330° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

Example 30

15 g of the soluble polyimide resin synthesized in Synthesis Example 13was dissolved in 35 g of dioxolane, thereby preparing an organic solventsolution so that its solid content weight ratio (Sc) was 30%.

An organic solvent solution of the photosensitive resin composition wasprepared by mixing the following components so as to produce aphotosensitive dry film resist in a B stage state.

(a) Soluble Polyimide Resin

-   Soluble polyimide resin synthesized in Synthesis Example 13 (in    accordance with conversion based on a solid content): 40 parts by    weight    (b) Phenoxyphosphazene Compound-   Circular phenoxyphosphazene compound synthesized in Synthesis    Example 5: 25 parts by weight    (c) (Meth)acrylic Compound-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈10) diacrylate (NK ester A-BPE-10    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.): 10    parts by weight-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈30) diacrylate (NK ester A-BPE-30    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.): 15    parts by weight    (d) Other Component

Photoreaction initiator

-   Bis (2,4-cyclopentadiene-1-yl)-bis (2,6′-difluoro-3-(1    H-pyrrole-1-yl)-phenyl) titanium (IRGACURE 784 (commercial name)    produced by Ciba Specialty Chemicals): 1 part by weight

Epoxy Resin

-   Bisphenol A type epoxy resin (Epikote 828 (commercial name) produced    by Japan Epoxy Resins Co., Ltd.): 10 parts by weight

Curing Agent

-   4,4′-diaminodiphenylmethane (DDM): 1 part by weight

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows. Flame retardancy test: The flame disappeared in4.0 seconds on the average, so that this was regarded as being proper.

-   Bleed: There was no bleed.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 310° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view.

Example 31

15 g of the double-bond polyimide resin synthesized in Synthesis Example14 was dissolved in 35 g of dioxolane, thereby preparing an organicsolvent solution so that its solid content weight ratio (Sc) was 30%.

An organic solvent solution of the photosensitive resin composition wasprepared by mixing the following components so as to produce aphotosensitive dry film resist in a B stage state.

(a) Soluble Polyimide Resin

-   Double-bond polyimide resin synthesized in Synthesis Example 14 (in    accordance with conversion based on a solid content): 50 parts by    weight    (b) Phenoxyphosphazene Compound-   Circular phenoxyphosphazene compound synthesized in Synthesis    Example 6: 25 parts by weight    (c) (Meth)acrylic Compound-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈10) diacrylate (NK ester A-BPE-10    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.): 10    parts by weight-   Bisphenol A type epoxyacrylate (Ebecryl 3700 (commercial name)    produced by DAICEL-UCB Company LTD.): 15 parts by weight    (d) Other Component

Photoreaction Initiator

-   Bis (2,4-cyclopentadiene-1-yl)-bis (2,6′-difluoro-3-(1    H-pyrrole-1-yl)-phenyl) titanium (IRGACURE 784 (commercial name)    produced by Ciba Specialty Chemicals): 1 part by weight

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows.

-   Flame retardancy test: The flame disappeared in 3.0 seconds on the    average, so that this was regarded as being proper.-   Bleed: There was no bleed.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 320° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

Comparative Example 3

Among polymers used instead of the soluble polyimide resin serving asthe component (a) in Examples 27 to 31, a polymer component having alargest weight in the photosensitive resin composition is referred to asa base polymer.

(Synthesis of Base Polymer)

173 g (0.30 mol) of ESDA and 300 g of DMF were placed in a 500 mlseparable flask provided with a stirrer, thereby preparing a DMF varnishof ESDA. Next, a solution obtained by dissolving 86.5 g (0.20 mol) ofBAPS-M in 100 g of DMF was added to the DMF varnish, and the mixture wasintensely stirred. After the solution became even, 83.5 g (0.10 mol) ofsilicondiamine KF-8010 (commercial name: product of Shin-Etsu SiliconeCo., Ltd.) was added thereto, and the mixture was intensely stirred.

The thus obtained polyamide acid solution was placed in a tray coatedwith fluorocarbon resin and was dried in a vacuum oven at 200° C. underreduced pressure of 660 Pa for two hours, thereby obtaining 315 g ofpolyimide resin.

The polyimide resin had no carboxyl group and/or no hydroxyl group inits imide resin. Further, no photosensitive group was introducedtherein.

(Production of Photosensitive Dry Film Resist)

15 g of the polyimide resin synthesized in the foregoing manner wasdissolved in 35 g of dioxolane, thereby preparing a varnish whose solidcontent weight ratio %(Sc) was 30%.

The same operation was carried out as in Example 27 except that thepolyimide resin synthesized in the present example was used instead ofthe component (a) of Example 27, thereby producing a photosensitive dryfilm resist.

(Evaluation of Properties)

Properties of the obtained photosensitive dry film resist were evaluatedas follows.

-   Flame retardancy test: The flame disappeared in 3.0 seconds on the    average, so that this was regarded as being proper.-   Bleed: There was no bleed.-   Developing property: Neither a hole of 100×100 μm nor a hole of    200×200 μm were developed, so that the photosensitive dry film    resist was regarded as being improper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 320° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

In this manner, when the polyimide resin having no carboxyl group and/orno hydroxyl group was used as a base polymer, the flame retardancy andthe heat resistance of the obtained photosensitive dry film resist werefavorable, but its developing property was not favorable.

Comparative Example 4

(Synthesis of Base Polymer)

Monomers of methylmethacrylate, n-butylmethacrylate,2-ethylhexylacrylate, and methacrylic acid were used as materials forthe polyimide resin. These monomer components were copolymerized inaccordance with a known method, thereby obtaining a copolymer having acarboxyl group. A polymerization ratio of the monomer components wasmethyemethacrylate/n-butylmethacrylate/2-ethylhexylacrylate/methacrylicacid=60/10/10/20 (in terms of a weight).

(Production of Photosensitive Dry Film Resist)

The photosensitive dry film resist was produced under the same conditionas in Example 28 except that the acrylic copolymer synthesized in thepresent example was used instead of the component (a) of Example 28.

(Evaluation of Properties)

Properties of the obtained photosensitive dry film resist were evaluatedas follows.

-   Flame retardancy test: The flame did not disappeared within 10    seconds, and the flame rose to the clamp, so that this was regarded    as being improper.-   Bleed: There was no bleed.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under the normal condition, the 30-second-dipable    temperature was 280° C. Under the moisture absorption condition, the    30-second-dipable temperature was 240° C. Thus, the photosensitive    dry film resist was regarded as being proper in this view point.

In this manner, when the acrylic copolymer made of a monomer having noaromatic ring was used as a base polymer, the developing property of theobtained photosensitive dry film resist was favorable, but its heatresistance was not favorable. Further, even when the phosphazenecompound was used, its flame retardancy was not favorable.

Comparative Example 5

(Production of Photosensitive Dry Film Resist)

The photosensitive dry film resist was produced under the same conditionas in Example 28 except that a propoxylated phosphazene compound(SPR-100 (commercial name) produced by Otsuka Chemical Co., Ltd.) wasused instead of the component (b) of Example 28.

(Evaluation of Properties)

Properties of the obtained photosensitive dry film resist were evaluatedas follows.

-   Flame retardancy test: The flame did not disappeared within 10    seconds, and the flame rose to the clamp, so that this was regarded    as being improper.-   Bleed: Bleeding was found.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 290° C.,    so that the photosensitive dry film resist was regarded as being    improper in this view point.

In this manner, when the phosphazene compound having no phenolichydroxyl group was used, the flame retardancy of the obtainedphotosensitive dry film resist was not sufficient, and thephotosensitive dry film resist had no reactive group. This resulted inbleeding and drop of the heat resistance.

[Preparation 2 of Photosensitive Resin Composition]

The soluble polyimide resin (K) having a carboxyl group and/or ahydroxyl group was dissolved in dioxolane, and its solid content weightratio %(Sc) was adjusted to 30%, thereby preparing a soluble polyimideresin solution. With respect to the solution, the phenoxyphosphazenecompound (L), the (meth)acrylic compounds (M), and if necessary othercomponent (L) were mixed/stirred, thereby preparing an organic solventsolution of the photosensitive resin composition so that its final solidcontent weight ratio %(Sc) was 50%. Here, the solid content weight ratiomeans a total weight of materials other than the organic solvent, thatis, a total weight of the components (K), (L), (M), and (N). Even aliquid material was regarded as the solid component.

[Production of Photosensitive Dry Film Resist]

The organic solvent solution of the photosensitive resin compositionobtained in [Preparation 2 of photosensitive resin composition] wasapplied to the support film so that thickness after being dried(thickness of the photosensitive dry film resist) ranged from 20 to 25μm. As the support film, a PET film (Lumirror (commercial name) producedby TORAY ADVANCED FILM Co., Ltd: its thickness was 25 μm) was used.Thereafter, the applied layer on the support film was dried at 100° C.for two minutes, thereby removing dioxolane. In this manner, a two-layersheet constituted of the photosensitive dry film resist/PET film(support film) was obtained. Note that, the photosensitive dry filmresist layer was in a B stage state.

Subsequently, a polyethylene film (GF-1 (commercial name) produced byTAMAPOLY Co., Ltd: its thickness was 40 μm) was roll-laminated on thephotosensitive dry film resist of the two-layer sheet at 20° C. and at anip pressure of 75000 Pa·m, thereby obtaining a three-layer sheet havingthree layers (the protective film, the photosensitive dry film resist,and the PET film).

[Evaluation of Properties of Photosensitive Dry Film Resist]

As to the organic solvent solution of the photosensitive resincomposition prepared in the foregoing [Preparation 2 of photosensitiveresin composition] and the photosensitive dry film resist produced, thefollowing properties thereof were evaluated. Specifically, theevaluation was carried out in terms of the flame retardancy, thedeveloping property, and the heat resistance. These properties wereevaluated in the same manner as in the evaluation of the organic solventsolution of the photosensitive resin composition and the photosensitivedry film resist that were obtained in

[Preparation 1 of Photosensitive Resin Composition].

Further, as materials of the soluble polyimide resin (K) having acarboxyl group and/or a hydroxyl group, not only the materials used tosynthesize the soluble polyimide resin (G-1) but also[bis(4-amino-3-carboxy)phenyl]methane (product of Wakayama Seika Co.,Ltd.: hereinafter, referred to as MBAA).

Further, a weight-average molecular weight of the soluble polyimideresin (K) having a carboxyl group and/or a hydroxyl group was measuredwith a high speed GPC (HLC-8220GPC produced by Tosoh Corporation), andwas calculated with a size exclusion chromatography in accordance withconversion based on polyethyleneoxide.

Synthesis Example 15 Synthesis of Soluble Polyimide Resin having aCarboxyl Group

17.3 g (0.030 mol) of ESDA and 30 g of dimethylformamide (hereinafter,referred to also as DMF) were placed in a 500ml separable flask providedwith a stirrer, and the mixture was stirred with the stirrer so that thestirred resultant was dissolved. Next, 5.15 g (0.018 mol) of MBAA wasdissolved in 9 g of DMF, and the resultant was added to the DMF solutionof ESDA, and the mixture was intensely stirred. After the solutionbecame even, 7.47 g (0.009 mol) of silicondiamine KF-8010 was addedthereto, and the mixture was stirred. After the solution became even,1.29 g (0.003 mol) of BAPS-M was added thereto, and the mixture wasintensely stirred for one hour. The polyamic acid solution obtained inthis manner was placed in a tray coated with fluorocarbon resin and wasdried in a vacuum oven at 200° C. under reduced pressure of 660 Pa fortwo hours, thereby obtaining 26.40 g of soluble polyimide resin having acarboxyl group. In the soluble polyimide resin, an acid equivalent was835 and a weight-average molecular weight was 37000.

Synthesis Example 16 Introduction of Methacryl Group into SolublePolyimide Resin having Carboxyl Group

20.0 g (0.020 mol) of the soluble polyimide resin having a carboxylgroup which had been synthesized in Synthesis Example 15 was dissolvedin 40 g of DNF, and 1.71 g (0.120 mol) of glycidyl methacrylate, 0.1 g(0.001 mol) of triethylamine, and 0.02 g ofN-nitrsphenylhydroxyaminealuminum salt serving as a polymerizationinhibitor were added, and the mixture was stirred at 80° C. for fivefours. The thus obtained solution was poured into 500 ml of methanole,and a deposited resin component was crushed by a mixer, and the crushedresins were rinsed with methanol and was dried, thereby obtaining 21.2 gof a soluble polyimide resin having a methacryl group. In the solublepolyimide resin, an acid equivalent was 1811 and a weight-averagemolecular weight was 38000.

Synthesis Example 17 Synthesis of Soluble Polyimide Resin havingHydroxyl Group

69.7 g (0.27 mol) of diamine DAM-1 and 100 g of DMF were placed in a 500ml separable flask provided with a stirrer, thereby preparing a DMFsolution of DAM-1. Next, 24.9 g (0.03 mol) of silicondiamine KF-8010 wasadded thereto, and the mixture was intensely stirred. After the solutionbecame even, a solution obtained by dissolving 173 g (0.30 mol) of ESDAin 300 g of DMF was added thereto, and the mixture was intensely stirredfor about one hour. The polyamide acid solution obtained in this mannerwas placed in a tray coated with fluorocarbon resin and was dried in avacuum oven at 200° C. under reduced pressure of 660 Pa for two hours,thereby obtaining 241.0 g of soluble polyimide resin having a hydroxylgroup. In the soluble polyimide resin, an acid equivalent was 475 and aweight-average molecular weight was 26000.

Synthesis Example 18 Introduction of Methacryl Group into SolublePolyimide Resin having Hydroxyl Group

100 g of the soluble polyimide resin having a hydroxyl group which hadbeen synthesized in Synthesis Example 17 was dissolved in 200 g of DNF,and 15.1 g (0.11 mol) of glycidyl methacrylate, 1.0 g (0.01 mol) oftriethylamine, and 0.02 g of N-nitrsphenylhydroxyaminealuminum saltserving as a polymerization inhibitor were added, and the mixture wasstirred at 80° C. for five fours. The thus obtained solution was pouredinto 500 ml of methanole, and a deposited resin component was crushed bya mixer, and the crushed resins were rinsed with methanol and was dried,thereby obtaining 113.4 g of a soluble polyimide resin having amethacryl group. In the soluble polyimide resin, an acid equivalent was1132 and a weight-average molecular weight was 30000.

Example 32

(Production of Photosensitive Dry Film Resist)

15 g of the soluble polyimide resin synthesized in Synthesis Example 15was dissolved in 35 g of dioxolane, thereby preparing an organic solventsolution so that its solid content weight ratio (Sc) was 30%.

An organic solvent solution of the photosensitive resin composition wasprepared by mixing the following components so as to produce aphotosensitive dry film resist in a B stage state.

(a) Soluble Polyimide Resin

-   Soluble polyimide resin synthesized in Synthesis Example 15 (in    accordance with conversion based on a solid content): 50 parts by    weight    (b) Cross-linked Phenoxyphosphazene Compound-   A cross-linked phenoxyphosphazene compound obtained by cross-linking    a circular phenoxyphosphazene compound, represented by formula (22)    where a is an integer ranging from 3 to 20, with a p-phenylene    group. SPS-100 (commercial name) produced by Otsuka Chemicals Inc.:    20 parts by weight    (c) (Meth)acrylic Compound-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n4) diacrylate (ARONIX M-211B (commercial    name) produced by TOAGOSEI CO., LTD.): 5 parts by weight Bisphenol A    EO denaturalized (recurring unit of an ethyleneoxide denaturalized    portion: m+n≈30) diacrylate (NK ester A-BPE-30 (commercial name)    produced by SHIN-NAKAMURA CHEMICAL CO., LTD.): 15 parts by weight    (d) Other Component

Photoreaction Initiator

-   Bis (2,4,6-trimethylbenzoyl)phenylphosphinoxide (IRGACURE 819    (commercial name) produced by Ciba Specialty Chemicals): 1 part by    weight

Epoxy Resin

-   Bisphenol A type epoxy resin (Epikote 828 (commercial name) produced    by Japan Epoxy Resins Co., Ltd.): 10 parts by weight

Curing Agent

-   4,4′-diaminodiphenylmethane (DDM): 1 part by weight    (Results of Property Evaluation)

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows.

-   Flame retardancy test: The flame disappeared in 3.5 seconds on the    average, so that this was regarded as being proper.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 330° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

Example 33

(Production of Photosensitive Dry Film Resist)

15 g of the soluble polyimide resin synthesized in Synthesis Example 16was dissolved in 35 g of dioxolane, thereby preparing an organic solventsolution so that its solid content weight ratio (Sc) was 30%

An organic solvent solution of the photosensitive resin composition wasprepared by mixing the following components so as to produce aphotosensitive dry film resist in a B stage state.

(a) Soluble Polyimide Resin

-   Soluble polyimide resin synthesized in Synthesis Example 16 (in    accordance with conversion based on a solid content): 50 parts by    weight    (b) Cross-linked Phenoxyphosphazene Compound-   A cross-linked phenoxyphosphazene compound obtained by cross-linking    a circular phenoxyphosphazene compound, represented by formula (22)    where a is an integer ranging from 3 to 20, with a p-phenylene    group. SPB-100 (commercial name) produced by Otsuka Chemicals Inc.:    20 parts by weight    (c) (Meth)acrylic Compound-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈4) diacrylate (ARONIX M-211B (commercial    name) produced by TOAGOSEI CO., LTD.): 5 parts by weight-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈30) diacrylate (NK ester A-BPE-30    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.): 15    parts by weight-   Epoxyacrylate (NK oligo EA-1010 (commercial name) produced by    SHIN-NAKAMURA CHEMICAL CO., LTD.): 10 parts by weight    (d) Other Component

Photoreaction Initiator

-   Bis (2,4,6-trimethylbenzoyl)phenylphosphinoxide (IRGACURE 819    (commercial name) produced by Ciba Specialty Chemicals): 1 part by    weight    (Results of Property Evaluation)

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows.

-   Flame retardancy test: The flame disappeared in 3.0 seconds on the    average, so that this was regarded as being proper.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 340° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

Example 34

(Production of Photosensitive Dry Film Resist)

15 g of the soluble polyimide resin synthesized in Synthesis Example 17was dissolved in 35 g of dioxolane, thereby preparing an organic solventsolution so that its solid content weight ratio (Sc) was 30%.

An organic solvent solution of the photosensitive resin composition wasprepared by mixing the following components so as to produce aphotosensitive dry film resist in a B stage state.

(a) Soluble Polyimide Resin

-   Soluble polyimide resin synthesized in Synthesis Example 17 (in    accordance with conversion based on a solid content): 50 parts by    weight    (b) Cross-linked Phenoxyphosphazene Compound-   A cross-linked phenoxyphosphazene compound obtained by cross-linking    a circular phenoxyphosphazene compound, represented by formula (22)    where a is an integer ranging from 3 to 20, with a p-phenylene    group. SPE-100 (commercial name) produced by Otsuka Chemicals Inc.:    20 parts by weight    (c) (Meth)acrylic Compound-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈10) diacrylate (NK ester A-BPE-10    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.)): 10    parts by weight-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈30) diacrylate (NK ester A-BPE-30    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.): 10    parts by weight    (d) Other Component

Photoreaction Initiator

-   Bis (2,4-cyclopentadiene-1-yl)-bis    (2,6′-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium (IRGACURE 784    (commercial name) produced by Ciba Specialty Chemicals): 1 part by    weight

Epoxy Resin

-   Bisphenol A type epoxy resin (Epikote 828 (commercial name) produced    by Japan Epoxy Resins Co., Ltd.): 10 parts by weight

Curing Agent

-   4,4′-diaminodiphenylmethane (DDM): 1 part by weight    (Results of Property Evaluation)

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows.

-   Flame retardancy test: The flame disappeared in 3.5 seconds on the    average, so that this was regarded as being proper.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 320° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

Example 35

(Production of Photosensitive Dry Film Resist)

15 g of the soluble polyimide resin synthesized in Synthesis Example 18was dissolved in 35 g of dioxolane, thereby preparing an organic solventsolution so that its solid content weight ratio (Sc) was 30%.

An organic solvent solution of the photosensitive resin composition wasprepared by mixing the following components so as to produce aphotosensitive dry film resist in a B stage state.

(a) Soluble Polyimide Resin

-   Soluble polyimide resin synthesized in Synthesis Example 18 (in    accordance with conversion based on a solid content): 55 parts by    weight    (b) Cross-linked Phenoxyphosphazene Compound-   Mixture obtained by mixing (i) a cross-linked phenoxyphosphazene    compound obtained by cross-linking a circular phenoxyphosphazene    compound, represented by formula (22) where a is an integer ranging    from 3 to 20, with a p-phenylene group and (ii) a cross-linked    phenoxyphosphazene compound obtained by cross-linking a chain    phenoxyphosphazene compound, represented by formula (23) where b is    an integer ranging from 3 to 1000, with a p-phenylene group. SPB-156    (commercial name) produced by Otsuka Chemicals Inc.: 20 parts by    weight    (c) (Meth)acrylic Compound-   Bisphenol A EO denaturalized (recurring unit of an ethyleneoxide    denaturalized portion: m+n≈10) diacrylate (NK ester A-BPE-10    (commercial name) produced by SHIN-NAKAMURA CHEMICAL CO., LTD.)): 10    parts by weight-   Bisphenol A type epoxyacrylate (Ebecryl 3700 (commercial name)    produced by DAICEL-UCB Company LTD.): 15 parts by weight    (d) Other Component

Photoreaction Initiator

-   Bis (2,4-cyclopentadiene-1-yl)-bis (2,6′-difluoro-3-(1    H-pyrrole-1-yl)-phenyl) titanium (IRGACURE 784 (commercial name)    produced by Ciba Specialty Chemicals): 1 part by weight    (Results of Property Evaluation)

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows.

-   Flame retardancy test: The flame disappeared in 3.0 seconds on the    average, so that this was regarded as being proper.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 320° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

Comparative Example 6

(Synthesis of Base Polymer)

Among polymers used instead of the soluble polyimide resin serving asthe component (a) in Examples 32 to 35, a polymer component having alargest weight in the photosensitive resin composition is referred to asa base polymer.

(Synthesis of Polyimide Resin)

173 g (0.30 mol) of ESDA and 300 g of DMF were placed in a 500 mlseparable flask provided with a stirrer, thereby preparing a DMFsolution of ESDA. Next, a solution obtained by dissolving 86.5 g (0.20mol) of BAPS-M in 100 g of DMF was added to 100 g of DMF, and themixture was intensely stirred. After the solution became even, 83.5 g(0.10 mol) of silicondiamine KF-8010 was added thereto, and the mixturewas intensely stirred for one hour.

The thus obtained polyamide acid solution was placed in a tray coatedwith fluorocarbon resin and was dried in a vacuum oven at 200° C. underreduced pressure of 660 Pa for two hours, thereby obtaining 315 g ofpolyimide resin. The polyimide resin had no carboxyl group and/or nohydroxyl group in its imide resin. Further, no photosensitive group wasintroduced therein.

(Production of Photosensitive Dry Film Resist)

15 g of the polyimide resin synthesized in the foregoing manner wasdissolved in 35 g of dioxolane, thereby preparing a varnish whose solidcontent weight ratio %(Sc) was 30%.

The same operation was carried out as in Example 32 except that thepolyimide resin synthesized in the present example was used instead ofthe component (a) of Example 32, thereby producing a photosensitive dryfilm resist.

(Results of Property Evaluation)

Properties of the thus obtained photosensitive dry film resist wereevaluated as follows.

-   Flame retardancy test: The flame disappeared in 3.0 seconds on the    average, so that this was regarded as being proper.-   Developing property: Neither a hole of 100×100 μm nor a hole of    200×200 μm were developed, so that the photosensitive dry film    resist was regarded as being improper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 320° C.,    so that the photosensitive dry film resist was regarded as being    proper in this view point.

In this manner, when the polyimide having no carboxyl group and/or a nohydroxyl group is used as a base polymer, the flame retardancy and theheat resistance were favorable, but its developing property was notfavorable.

Comparative Example 7

(Synthesis of Base Polymer)

Monomers of methylmethacrylate, n-butylmethacrylate,2-ethylhexylacrylate, and methacrylic acid were used as materials forthe polyimide resin. These monomer components were copolymerized inaccordance with a known method, thereby obtaining a copolymer having acarboxyl group. A polymerization ratio of the monomer components wasmethylmethacrylate/n-butylmethacrylate/2-ethylhexylacr ylate/methacrylicacid=60/10/10/20 (in terms of a weight).

(Production of Photosensitive Dry Film Resist)

The photosensitive dry film resist was produced under the same conditionas in Example 33 except that the acrylic copolymer synthesized in thepresent example was used instead of the component (a) of Example 33.

(Results of Property Evaluation)

Properties of the obtained photosensitive dry film resist were evaluatedas follows.

-   Flame retardancy test: The flame did not disappeared within 10    seconds, and the flame rose to the clamp, so that this was regarded    as being improper.-   Bleed: There was no bleed.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under the normal condition, the 30-second-dipable    temperature was 280° C. Under the moisture absorption condition, the    30-second-dipable temperature was 240° C. Thus, the photosensitive    dry film resist was regarded as being proper in this view point.

In this manner, when the acrylic copolymer made of a monomer having noaromatic ring was used as a base polymer, the developing property of theobtained photosensitive dry film resist was favorable, but its heatresistance was not favorable. Further, even when the phosphazenecompound was used, its flame retardancy was not favorable.

-   [Comparative Example 8]    (Production of Photosensitive Dry Film Resist)

The photosensitive dry film resist was produced under the same conditionas in Example 33 except that a propoxylated phosphazene compound wasused instead of the component (b) of Example 33.

(Results of Property Evaluation)

Properties of the obtained photosensitive dry film resist were evaluatedas follows.

-   Flame retardancy test: The flame did not disappeared within 10    seconds, so that this was regarded as being improper.-   Developing property: Both a hole of 100×100 μm and a hole of 200×200    μm were developed, so that the photosensitive dry film resist was    regarded as being proper in this view point.-   Heat resistance: Under both the normal condition and the moisture    absorption condition, the 30-second-dipable temperature was 290° C.,    so that the photosensitive dry film resist was regarded as being    improper in this view point.

In this manner, when the propoxylated phosphazene was used, the flameretardancy of the obtained photosensitive dry film resist was notsufficient. Further, this resulted in drop of the heat resistance.

TABLE 1 Examples 32 33 34 35 Soluble polyimide resin Synthesis SynthesisSynthesis Synthesis (part by weight) Example 15 Example 16 Example 17Example 18 50 50 50 55 Cross-linked phenoxyphosphagene 20 20 20 20 (partby weight) (Meth)acrylic compound 20 30 20 25 (part by weight)Photoreaction initiator 1 1 1 1 (part by weight) Epoxy resin (part byweight) 10 10 Curing agent (part by weight) 1 1 Flame retardancy testProper Proper Proper Proper Developing property Proper Proper ProperProper Heat resistance Proper Proper Proper Proper

TABLE 2 Comparative Examples 6 7 8 Soluble polyimide resin Synthesis(part by weight). Example 16 50 Polyimide resin having 50 no carboxylgroup and/or no hydroxyl group (part by weight) Acrylic copolymer 50(part by weight) Cross-linked 20 20 phenoxyphosphagene (part by weight)Propoxylated phosphazene 20 (part by weight) (Meth)acrylic compound 2030 30 (part by weight) Photoreaction initiator 1 1 1 (part by weight)Epoxy resin 10 (part by weight) Curing agent 1 (part by weight) Flameretardancy test Proper Improper Improper Developing property ImproperProper Proper Heat resistance Proper Improper Improper

The embodiments and concrete examples of implementation discussed in theforegoing detailed explanation serve solely to illustrate the technicaldetails of the present invention, which should not be narrowlyinterpreted within the limits of such embodiments and concrete examples,but rather may be applied in many variations within the spirit of thepresent invention, provided such variations do not exceed the scope ofthe patent claims set forth below.

INDUSTRIAL APPLICABILITY

As described above, each of the phosphazene compound and thephotosensitive resin composition according to the present invention hasfavorable water system developing property (developing property in basicaqueous solution) and allows both (i) properties such as heatresistance, anti-hydrolysis property, easiness to process (inclusive ofsolvent solubility), bonding property, and (ii)photosensitivity, flameretardancy, and sufficient mechanical strength, the phosphazene compoundand the photosensitive resin composition being favorably applicable toproduction of a wiring board which can sufficiently cover smaller andlighter electronic parts of electronic devices. Thus, in case where thephotosensitive resin composition according to the present invention isformed into a varnish-like solution or the like, it is possible to usethe solution as an effective resin chemical product constituting anadhesive, a coating agent, an ink, or the like. Further, in case wherethe photosensitive resin composition according to the present inventionis formed into a resin sheet or a resin film, it is possible tofavorably use the photosensitive resin composition as a print wiringboard (FPC) adhesive sheet, a pattern circuit resist film, aphotosensitive cover lay film, a photosensitive dry film resist, a printwiring board insulative circuit protection film, a print wiring boardsubstrate, or the like.

Thus, the present invention can be used not only in various resinindustries and chemical industries for producing photosensitive resincompositions but also in resin processing industries for producing resinchemical products and laminates etc. and electronic part industries andelectronic device industries for producing/using circuit substrates andthe like.

1. A phosphazene compound, obtained by reacting a phenoxyphosphazenecompound (A-1) having a phenolic hydroxyl group and/or a cross-linkedphenoxyphosphazene compound (A-2) obtained by cross-linking thephenoxyphosphazene compound (A-1) with an epoxy compound (B) having anunsaturated double bond, wherein the phosphazene compound has anunsaturated double bond and a phenolic hydroxyl group in its molecule;and the epoxy compound (B) is at least one epoxy compound selected fromthe group consisting of glycidylmethacrylate, glycidylacrylate,allylglycidylether, glycidylvinylether, and a compound represented bythe following formula (10)

wherein r represents an integer ranging from 0 to 40, and R⁸ representsH or a methyl group.
 2. The phosphazene compound as set forth in claim1, wherein the phenoxyphosphazene compound (A-1) is a circularphenoxyphosphazene compound (A-11) represented by formula (1)

where m represents an integer ranging from 3 to 25, and each of R¹ andR² represents a phenyl group or a hydroxyphenyl group, and a singlemolecule has one or more hydroxyphenyl groups.
 3. A photosensitive resincomposition, comprising at least the phosphazene compound as set forthin claim 1 and a soluble polyimide resin (D) which is soluble in anorganic solvent.
 4. The photosensitive resin composition as set forth inclaim 3, further comprising a photoreaction initiator (E-1).
 5. Aphotosensitive resin composition, comprising at least the phosphazenecompound as set forth in claim 1 and a photoreaction initiator (E-1). 6.The photosensitive resin composition as set forth in claim 3, furthercomprising a compound having a carbon-carbon double bond (E-4).
 7. Thephotosensitive resin composition as set forth in claim 3, wherein 1 wt%or more of the soluble polyimide resin (D) is dissolved in at least onekind of an organic solvent selected from dioxolane, dioxane,tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, andN-methyl-2-pyrrolidone at temperature ranging from room temperature to100° C.
 8. A photosensitive resin film, being formed by using thephotosensitive resin composition as set forth in claim
 3. 9. Thephotosensitive resin film as set forth in claim 8, being used as a printwiring board adhesive sheet, a photosensitive cover lay film, a printwiring insulative protection film, or a print wiring board substrate.